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I like how this article is laid out as first defining the existing systems used today since while it’s all I know, I haven’t spent the time defining it. And then describes a number of inspirational examples of how it could be different.

Desktop file systems seem impossibly hard to change at this point, but cloud storage and mobile file systems are still so new and not amazing in my opinion - there’s still hope for a better experience.

I've been hearing this for years, but I've never had the mental model for it. Maybe I just have to try it out.

There's a very neat project (can't remember the name, and some details below may be wrong,) that mounts a FUSE filesystem that uses only tags.

Paths have identical syntax to hierarchical ones, only each segment of a path is a tag.

so `/document/taxes/2020` would return a collection of files, but you could also write `/taxes/2020/document` and it would mean the same thing.

The advantage is you can use standard unix tools like ls, mv, cp, etc. as well as R/W using standard programs (like how you'd export an image.)

I'm sure there's edge cases to it, but I always found the idea very neat. Anyone remember what I'm talking about?

While I don't remember that specific project's name, I do remember that a lot of that was possible because files in a filesystem often aren't just some hierarchical folder structure. There is often a tree-like structure to be able to find a single file quickly amongst many files, but there was no technical reason why it wouldn't also support off-tree indexing based on tags.

I imagine one of the problems you'd run in to is mass updates since deleting a directory with many files in it below a single tree node is very much limited to that part of the filesystem's tree, but doing it with tags causes updates all over the place.

It does remind me of this more metadata-like FS: https://github.com/marook/tagfs

As well as the thing Apple does in Finder where it has a tag database and dynamic 'tag' directories where it shows you everything that was tagged with that tag. Then the search function would allow selecting files based on tags so you can do many-tag searches and only find the files that match all of them. I think that one is based on an in-filesystem metadata stream.

I think the article was about making it easier for users. It may not be easy anymore if they have to use directories AND tags. Or it may work, if the only files they normally tag are their documents.

Tags have a problem with names. How do you stop users from messing with files that belong to the OS or some application? Should we require that they all have the tags "OS" or "app" on them? Should binaries have the tag "binary"? What happens when the user tries to delete one app but chooses "tag 'app' and name startswith 'word'"? Should all application files named "word"-something from different applications be removed? Should the user have known to use a meta-query with "tag 'app' and tagname:startswith 'word'"?

I do see a lot of problems but of course some things would be easier.

At least that part of the puzzle is obvious:

Users should never touch system files nor have to look at them. I never want to see any asfawe.sdwae file ever again. Its like keeping power tools in the cup board or having screwdrivers in your utensils drawer. Its like keeping the manual in the washing machine. You open the door and instantly know it's a ridiculous idea.

The user should be able to do what he wants, anything should go, there should not be any bad moves besides deleting their own stuff, they should be able to simply delete everything. Make it a partition with a warning prompt.

> I've been hearing this for years, but I've never had the mental model for it. Maybe I just have to try it out.

Gmail uses tags rather than folders, nice easy way to have a play if you've already got a google account.

Conceptually, I think of it as basically being able to have lots of different hierarchical folder structures applied to a set of objects at the same time. Or to flip it round, a normal folder structure is like using tags but where you are limited to one tag (the folder that holds the object) per object.

Not exactly. In Gmail, tags are hierarchical.

So, if I have a tag called 'projects', and another tag called 'newproject', the overall tag is 'projects-newproject'.

If I try to see everything under 'projects', it'll only show me the ones tagged 'projects' directly, not the ones under 'newproject'.

I think what you're seeing is the opposite: tags aren't hierarchical. Tags can be organized hierarchically, for organizational purposes, and you can use rules to ensure that everything tagged "projects-FOO" is also tagged "projects", but the tags as they apply to tagged objects aren't hierarchical.
This is only if you use it hierarchically. No one prevents you from having a tag projects and another tag newproject. Your emails just have both tags assigned and you are good to go
From a document perspective, yes, you're correct.

From a tagest perspective, and the discovery affordances, there is a significant difference.

Hierarchical tagsets allow you to navigate via tags, affording document discovery by that mechanism.

That becomes more significant as you're working with a larger, richer, and more structured tagset.

Sure, but GP's point (and it's something that annoyed me in Fastmail too) is that if you do have an 'hierarchical tag' - which could be in addition to unrelated tags - you don't get the '<sub-tag> is a <super-tag>' that you might expect.

The tags themselves end up in an hierarchy without it affecting the tagged contents.

> I've never had the mental model for it.

This is one way to think about the hybrid model of folders + tags that is currently available:

1. Folders tell you where the file is stored.

2. Tags tell you what is the file.

So basically use the Tags to add more data (metadata) about your files, so that if you forget where the file is, you can still search for it by what is in it. This also slightly helps in easing the burden of trying to figure out where to store a file (e.g. "Do I put a home video in my 'Videos' folder or my 'Personal' folder?" - if you tag it properly, you can put it in either, as you can use the tags to figure out where the video is later).

Examples:

1. In Documents folder - "mom-2020.xls" (tags => docs, tax, finance, mom, unfiled).

2. In Videos folder - "newyear bash.mp4" (tags => video, family, 2021, home).

Don't think I ever had it explained this clearly to me lol. Thank you! I run Mac os so I might give tagging a try now
10 years ago I was prototyping something very similar for Windows.

If I recall, CBFS and Dokan were the closest things you had to FUSE on Windows back then. Alternatively considered emulating a network drive. Like you pointed out, it had to be transparent to your existing software's Open / Save dialogs (although there was some effort to hook the standard ones to give users a place to apply tags when saving).

We've been stuck in the same old directory paradigm for a long time. There are some use cases where the traditional hierarchical approach is desirable (e.g. when you need to "visit" a set of files exactly once, like to browse through a folder to clean it up, enumerate for backup, calculate sizes, etc). But it's a constraint when a file belongs in more than one place.

There's a Windows component for this now - Projected Filesystem (projfs).
The downside of folders is trying to figure out where things belong in the hierarchy, or trying to update that hierarchy to a new standard.

The downside of tagging is you still need to establish conventions to ensure things can be found again, but enforcement of your conventions is harder.

Exploring, learning, and using an unfamiliar folder hierarchy is easier than exploring, learning, and using an unfamiliar tagging methodology.

But manually searching for something in somebody else's tagged data is easier than manually searching for something in somebody else's folders.

> The downside of folders is trying to figure out where things belong in the hierarchy, or trying to update that hierarchy to a new standard.

That's why I stick to Documents/{folder1..folder∞} and folders don't have hierarchical sub folders, just contextual folders. Eg: Documents/taxes 2021/{invoices, stuff}, Documents/taxes 2021/, Documents/Cthulluh Roleplaying/{pdf files of characters}, Documents/Covid vaccination certificates,

Yes, it's messy but I don't have the mental burden of a holding a tree in my head or a tagging system.

I try not to go more than three folders deep (starting from ~). I don't mind a lot of files in a folder, search helps me with that.
My current setup is: Documents, owncloud, Downloads, Dev, Media and tmp. No desktop. At work I have an additional git folder.
It seems that for any DAG, a hierarchy could be derived that would minimized either the number of soft-links, or a weighted score of how many contained files are in a soft-linked path.

And, similar to how a sugiyama graph automatically redraws when an edge is added or removed, a filesystem hierarchy could be automatically restructured to minimize the above scores when files are added or removed from the various folders.

At it's simplest, a filesystem can be thought of as a string key (small) to value (large blob) database.

Directories are just a method of breaking the collection into usefully small / specific subsets for humans (mostly) and computers (a secondary but important performance optimization).

There's no technical reason some form of Standard couldn't be added to, or on top of, a filesystem that added tags as an alternate view or foreign index against the data.

The holdup is that there isn't any single standard for adding or searching by tags. The current directory structure is the lowest common denominator and has existed for longer than many of us have been alive. Change is _hard_ and those file open/close dialogues and interface methods still have to work, and they can work, at least for limited numbers of tags or maybe by some addition / removal special path syntax... However then it's stupid hard for the humans. Hard for the use case the tags are supposed to simplify.

Maybe this change can be added to what everyone really needs: a set of GUI calls that work on all the platforms, that isn't writing a damned web-page and using a DLL-hell-bloat bundled web-browser to do the cross platform lifting. Something that can work across all the desktops (as a target) and maybe all the mobiles (as another target) and maybe tablets too (slightly different target, somewhere between).

ahhh you mean like a json api for the browser!</sarcasm>
I think the api that allows for more flexibility of implementation underneath is a hierarchical multi tag system with one root of the tag reserved for the existing filesystem, eg. "fs". Paths on /fs/dir/dir/file could serve as definitive storage reference and a way into the existing filesystem apis, while other tag systems can be imposed by the user in parallel trees of tags - all of which refer to the underlying fs tree under their implementations.
This might work for documents but a difficulty I see is how you would handle system files. See, with documents it's fine to always return a collection of files, but for a system file say /etc/passwd, you want to make sure you get exactly (status quo guarantees at most which is almost but not quite as good) one file.
Just think of the endless possibilities of a node_modules folder replaced with some tags! /s
My favourite file organization hack is to have a "scratch" folder containing everything that I can lose with no problem. Stuff only comes out of the scratch folder if I know I can't redownload it again and I might need it.

This way I can just wipe the whole scratch folder whenever I want, and there are much less files I actually need to organize.

Similar but mine is ~/tmp and I have a cron job that deletes any files/folders over 30 days old.
Oh man, that's smart. Would you mind sharing that script?
(comment deleted)
You could use something like this:

   find /tmp -type f -mtime +30 -delete
Sounds like a really bad idea for tools like mv and rm. Suddenly you have moved or deleted much more than you thought. Unless you support guids or similar also but end users are normally really bad at reading and writing those. It is very easy to mistake one guid for another.
The same is happening in webshops. Products can be assigned to hierarchies (categories) but in shops like Amazon it is obvious it is more like tagging.
In ecommerce, products are often presented to the shopper by search facets, so kind of all of the above applies.
And amazon thanks to that is opaque, I never look around for stuff, just search and find or not. They could have made something better where you can discover other stuff.
ok, maybe this is the right thread for this question: Anyone has a good structure for their own mp3s? I'd imagine tagging all files and using those tags for playlists would be a good way to do it. Does anyone do something like this or similar and can give pointers?
Run an old version of iTunes in a VM?

The column browser is still one of the generally best media browsing interfaces I've ever dealt with.

Use MusicBrainz Picard.

The MusicBrainz database is probably the best there is, and it does a good job of automatically tagging your music. Once tagged, every file will have a unique musicbrainz_trackid (UUID) in its metadata, which can be used to recover/update the metadata associated with the track automatically from the database, which is constantly updated (and to which you can contribute if it is missing metadata for your tracks).

You can configure Picard to arrange files and rename them however you want. It has some simple scripting functionality so you can name things conditionally based on the presence or absence of metadata, etc. [https://picard-docs.musicbrainz.org/en/tutorials/naming_scri...]

If you are concerned about privacy, you can run your own musicbrainz instance in a VM and download a copy of the entire database.

Picard is extensible with Python. There's some existing plugins for generating playlist files.

A complementary alternative I'd suggest is beets[1], a front-end agnostic CLI tagging utility that also matches your files against the MusicBrainz database and can both correct the ID3 tags and maintain a directory hierarchy based on those tags.

The biggest shortcoming of the MusicBrainz database I've found so far, however, is genre tags. Most releases seem to have only one or a handful of genres listed with no consistent genre hierarchy convention, but I've been experimenting with an extensions that pulls genre tags from discogs.

1. https://beets.readthedocs.io/

I guess I'll need to blog about it because I can't find any information online, but still nothing has beat Sony's SonicStage, which is by most accounts very annoying proprietary software for working with minidisc players that want ATRAC encoding, but also included an excellent tag navigator that worked like so:

While playing any song in your library, you could display a graph view which showed the song center screen, and radially arranged spokes enumerating what the song was tagged with, "rock", "instrumental", "upbeat" etc, and when you clicked that tag, it would become center-screen and all the songs with that tag would be radially arranged around that tag. So you could navigate your library by kind of surfing the tag-graph and hit play/add to playlist as you go.

Last I checked there were .exe's compatible with Windows 10 available so I'll have to download it again and try it out.

I think the author is just a little bit behind the times in terms of organizing large corpuses of inter-related data. Tagging as a general idea is too fast-and-loose without a system/structure to organize the tags. Semantic Web stacks are one way to improve on this using taxonomies and ontologies, query languages and data specs; they almost mention it in the alternative systems ("touples") but don't dig into just how hard it is to manage data using unstructured references (or even structured ones!).

Simple hierarchies are ..... simple. Tags are simple too, but they quickly devolve into new complexities as people try to figure out how to apply them, find them, organize them. Hierarchies aren't typically as difficult to manage because it boxes you into re-creating the same mental model for organization, just with different classifiers for each level of the hierarchy. They're less flexible, but they're easier to grok, maintain, and use.

My major concern is that there isn't really a need to "fix" hierarchies, it's just a nagging problem that someone doesn't want to deal with, so their solution is to make something more complicated.... and more complicated might not make it better. It should also be feasible to design applications to organize the files without having to rewrite filesystems.

You seem to know a lot about this; what is considered the "correct" way to organize data like this these days?
I couldn't claim to know what is "correct" and what isn't! I've just worked on projects to organize large collections of interrelated datasets (for example, to update correlations between concepts, to make search engines more effective, to identify related or dependent item relationships, etc) and for our project we used a Semantic Web stack. Browsing GitHub for "knowledge graph" or "knowledge management" seems to pop up some cool looking projects, but I think everyone is still trying to figure out what works for a particular use case rather than generally.

I hope a real data scientist can reply with whatever the latest and greatest solutions are. Semantic Web tech for knowledge graphs are continuing to evolve, but also kind of old, and they're still mostly used for research projects. Part of that is probably because the terminology is unusual, and implementation leads you down a long rabbit hole of new and confusing concepts. So that's why I'm thinking that just sticking to a boring inefficient hierarchy might not be so bad...

(comment deleted)
Tags vs. Hierarchy are like the WFH vs. Office debate: something people assume has a right answer but is actually personal preference.
I don't think it is just a preference for system files and application files. For documents, sure.

Think about an application that tries to find the settings file. Which tags should it use in the search? How does the user know that no other file on the computer will suddenly be found because they used the same set of tags?

It would not happen - uniqueness would be enforced by the file name and its set of tags. Only one match could exist.
Wasn't this the intent behind Windows Vista - a tag-based DB-as-filesystem with hierarchical paths just one "lens" through which to view the DB? I use Google Drive this way, largely through search rather than directory-based organization, though I do also employ that for often-used collections.
It's the entire point of MS SharePoint afaict: create a tag based FS on top of some SQL database.
ok well if its the entire point of sharepoint I can conclude that tags suck and go read something else because, well, sharepoint.
Reminds me of an old project I did where I built a fuse system for this, files still lived on a normal ext3 fs, but the overlay presented files as tag paths, yo you could access, for instance, a movie like /tagfs/movies/year/1999/matrix.avi or /tagfs/movies/genre/scifi/matrix.avi

There was a special path /tagfs/untagged/ which listed any files that didn't have at least one tag.

From the article:

> ### Hard and soft links as non-solutions

> Soft links have a nearly opposite set of problems as hard links – soft links can span different file systems, but they generally don’t track the target files getting moved or renamed (except that Windows provides such a system service, but may not be reliable); while hard links are all indistinguishable, some application software behaves differently on soft links than on real hard-linked files. In spite of these problems, hard and soft links still require an exponential amount of effort to classify a set of files in multiple ways, and require the user to manually remember all the possible paths that a file can be reached from (important when editing and removing files, not important when browsing/retrieving files). They are non-scalable kludges compared to true tagging.

As a fan of hierarchies for file organization, and as someone with quite literally thousands of soft links, when I read things like this, I don't know if the person arguing against links has tried this approach. It works totally fine for me.

Yes, with soft links, moving the original file breaks the links. I wrote a fairly simple bash script to automatically fix these for my reference PDF files. It works because each PDF file I save has a unique file name. So figuring out where the links need to point is pretty simple. That makes me a "power user", I guess, but the author is at least at the same level and I think could figure it out.

With respect to the "exponential amount of effort to classify a set of files in multiple ways", I guess the author is referring to navigating the hierarchy to link a file in multiple places? I use tagging at my work, and I personally find scrolling through my list of about 200 tags to be comparable in terms of time to navigating through a hierarchy. The bottleneck is the human.

Edit: Here's another article by someone who is not a fan of links: https://karl-voit.at/2018/08/25/links/

I use hard and soft links (mostly the former for files and the latter for directories) and I think it works very well in practice despite the theoretical problems brought up.
tags are great when you know what you're looking for but are terrible for browsing a new dataset.

this is especially true when you're the newbie eg on a project and you didn't have any input into the tag structure.

This. Hierarchy allows a simple manual traversal, leading to better discoverability.
Any tag based system should have a breadcrumb function that allows for manual traversal.
I've recently built a tagging system based on SKOS [1]. This supports hierarchical as well as associative relationships between tags (while not strictly requiring either), as well as ad hoc groups of tags.

While SKOS was intended for more formal vocabularies, I've found its use as a basis for a tagging system makes exploration and navigation of a topic area reasonably organic, as it allows users to specify relationships only as they see as fit and intuitive.

[1]: https://www.w3.org/TR/skos-primer/

There just needs to be a default view that shows you the most important tags to start from - either by most used files, or largest number of files, or most active recent changes, or as managed by someone. The nice thing about tags is all of those could be top level tabs and you are sailing.
Tags are superfluous if you have a good search engine. Hierarchy isn't.
Yeah, tagging really seems like the job of a file manager (and indexer) rather than a file system. That seems like an easy way to get everything we want without rewriting billions of lines of code that deal with hierarchies.
Tags (or other metadata) are:

- A controlled vocabulary. This addresses the problem of numerous terms referring to the same concept, the same terms applying to different concepts, disagreements on spelling or charactersets, and standardisation or cross-references between multiple terms.

- Externally applied, subject to authority independent of an author or publisher. This addresses the problem of keyword-stuffing.

- Capable of referencing information not within a document itself. Its place of publication, earlier or later versions, cultural context, citations, amongst others.

- Can be applied to nontextual media: images, audio, video, data.

Tags themselves are not hierarchical.

Search is not introspective or contextual.

Tags could be a controlled vocabulary, but in almost all cases they are free-for-all.

Archive of Our Own has an interesting scheme, where authors tag their pieces freely, and volunteers behind the scenes enrich those pieces with tags that are indeed from a controlled vocabulary.

(They also do other mind-boggling stuff: in those tags they encode all kinds of information, so that you can search for a Kirk-Spock love story where violence is involved and Spock is dominant, and so on…)

I could have been clearer, but tags, even in a highly informal process, *are supplied by the reader(s) or curator(s) rather than the author/publisher, at least in the context of organising one's own archive. In that sense, tags are, even if not highly structured, a controlled vocabulary.

(I'm not referring to tagging that's provided by a publishing site itself, though yes, that's a fairly common practice. Tagging by a skilled third-party curator or librarian can of course be excellent.)

> Search is not introspective

What?

For tags I use meta data, which are included as mapped text at the extreme end of many media formats. For example ID3 data on MP3 files.

I have found this incredibly helpful for MP3s because I have thousands of them and there are many similar names. Windows Explorer provides columns for this data in its detailed file system view (not by default) which is incredibly helpful and trivial to customize.

For everything else folders are enough. I have hundreds of movies on a hard disk and yet folders are enough. When I do need more the data I want is generated by the file system: last modified, file size, and so forth.

What improves file usability the most for me is network access by meta data. For example Windows Explorer and OSX Finder are nice but I would rather have the exact same interface on the same local machine for a bunch of remote machines regardless of their file system or operating system. Then copy to a different machine is just drag and drop from one window onto another in an application that looks like some local OS, that windowing interface needs to allow sorting and filtering and search by meta data just like Windows Explorer. Having an application that does this for me has been great.

I love Bear with it’s 1+ hiearchical tags per note. It’s the perfect combination of both worlds for me. Would encourage the author to check it out (if it’s any different).
Librarians have been classifying the world's knowledge since forever, and they developed faceted classification systems (Ranganathan, 1933) to deal with these issues.

https://www.researchgate.net/publication/321840994_Ranganath...

A notable one that hierarchies embed the point of view of the classifier, e.g. the Dewy Decimal's ridiculous classifications of religions (codes 200–299), making minute distinctions like 285 (Presbyterian, Reformed, Congregational), 286 (Baptist, Disciples of Christ, Adventist), then putting all non-Christian religions under a handful of afterthought headings 292–299: 294 for Hinduism, Buddhism, Sikkhism and other religions of Indian origin, 295 for Zoroastrianism and its descendants, 296 for Judaism, 297 for Islam and Bahaism lumped together, and 299 for New Age.

Unfortunately, most of us do not have access to the services of a librarian to develop a taxonomy that corresponds to our own point of view then classify our files accordingly, which is why simple hierarchical taxonomies have endured and faceted ones seldom beyond specialized applications like Digital Asset Management.

Dewey Decimal System has only one (often-misunderstood) task: organizing bookshelf space. It does not have a task of classifying world information.

The reason that fairly narrow "Presbyterian, Reformed, Congregational" topic has one DDS code and an extremely wide "Hinduism, Buddhism, Sikkhism and other religions of Indian origin" topic has one DDS code is simple: an average library has similar book-width for both topics.

An average American library, you mean.
Of course, and while we are there, an average American Public library as of the end of the 19th century.

In the last century, DDS has seen its adaptations for China, Japan and other countries which are based on the same idea but are rather different.

> Dewey Decimal System has only one (often-misunderstood) task: organizing bookshelf space. It does not have a task of classifying world information.

How is this distinct from organizing world information? If the goal is to shelve books in a way that adds value to the information-seeker, you have to arrange them according to some definition of similarity. That decision about what makes one thing similar to another encodes a view of the world.

The physical shelves in a library only serve a single, small geographic area, not the whole world.
inter-library loans beg to disagree.
Does the shelving system of the library that owns the book matter to the library requesting it?
Perhaps only in that books are sometimes lost for years due to being put back in the wrong place! ‘Defragmenting’ the shelf space in a public library is a long and painful task, both for when there is a lack of room and for when things get out of order!
has anyone considered adding a series of color bands to the labels for coarse/medium/fine grained placement information? For example "coarse" is nonfiction, "medium" is travel, and "fine" is Bermuda, or whatever. If you see a book with a red label in the blue section, or whatever, you know it's misplaced.

If the labels are placed on the book at a similar location, then any book that is out of its proper would be significantly more obvious without having to resort to reading the label of every single book.

Of course the techie solution would be to barcode every book and then have a robot on each shelf that scans the barcodes after hours...

Books come in all sizes and shapes, so scanning that color coded labels is still going to be a pain...
index them from the bottom of the book spine - if they're always 0.5" off the bottom of the shelf, it doesn't matter how tall the book is.
I've usually seen this done with colored dot stickers affixed near to or on the library label on the spine of the book.
ILL is a distribution, not a storage, mechanism.

The DDS codes subject to shelf location. For a given library, materials selection is largely relevant to its own interests, and in many cases, location and local culture have a strong influence over that.

(As I've discussed in an earlier comment, DDS is not the only shelving system used, though it's a commonly encountered one in the US, and serves as a basis for numerous others. There are also non-subject based shelving systems, though those are typically not publically-accessed.)

> The physical shelves in a library only serve a single, small geographic area, not the whole world

What part of that sentence is not contradicted by inter-library loans? The books come off the shelves, and must be found there. They serve a wide geographic area, sometimes even the whole world (my mother was a librarian at several very specialized libraries and they participated in both receiving and giving loans involving other libraries around the world. It is true that the physical shelves in a library in (say) Germany will not be organized using DDS, but it remains true that the physical shelves can serve a wide geographic area.

And this is not even to comment on those specialized libraries that people will travel from around the world to visit. Same physical shelves, world-wide service area. These can include libraries focused on individuals (famous historical figures, for example), or academic libraries with particularly rich holdings in certain areas, or libraries that just happen to have the only instance of a set of books/documents.

The Dewey Decimal Classification (DDC) is not a special-holdings cataloguing system. It is not even an academic holdings cataloguing system (in the US the Library of Congress Classification System, LCSS, is overwhelmingly used for this). DDC is used, in the majority of cases, for public libraries, serving local communities, in the US.

The fact that DDC was developed at an academic library (Amherst College Library) doesn't refute this --- origin stories are not present-use stories, and Amherst have largely converted to the LCCS (see: https://www.amherst.edu/library/find/finditfrost/call-number... https://www.amherst.edu/library/find/finditfrost#tab-44437).

The LCCS, though influenced by DCC, is distinct. It still reflects a US-centrism, though with different emphasis. History of the Americas occupies two of the twenty alphabetic major classifications, and each of political science, law, education, agriculture, technology, military, and (separately) navel science, has its own major classification, reflecting the interests of a government ... and that government's library shelving concerns.

Specialised libraries rarely use DCC in my experience. Medical libraries often use their own specific classification, and academic libraries in the US as noted above typically use LCCS, though some retain DCC or their own ideosyncratic classifications (both are generally being phased out for LCCS).

For the University of California, an academic library with a strong inter-campus ILL programme, local circulaty exceeds ILL within the multicampus system by over an order of magnitude (1.6 million vs. 135k https://libraries.universityofcalifornia.edu/about/facts-and...). For a local public library with few exceptional holdings, ILL circulation is likely a far smaller fraction of circulation. (Some have regional lending arrangements with peer libraries, independent of ILL. This still remains a small fraction of total circulation.) Much use of materials is within the library itself, captured only (if at all) in reshelving statistics, though those are hard to find.

(I used the UC library system only because it's among the few that have available statistics.)

The point remains that the principle focus of a cataloguing system is for local use and management of a bibliographic collection. ILL happens to be an incidental and compatible use. It is not of itself a major factor in classification system development.

If you have any substantive argument to the contrary, I'd be happy to hear it. You've not yet made one.

That's a lot of good information about library classification systems. But none of of it seems to impinge on this sentence:

> The physical shelves in a library only serve a single, small geographic area, not the whole world

which is the line I was responding too.

If 90%+ of your use case (for a major academic library) is local, and <10% is remote (though within the same general geographical region and topical interests), do you solve for the <10% solution or the >90% solution?

If you're a regional nonspecialist nonacademic library where that split is far more likely 99%/1%, which do you solve for?

I am telling you flatly that your assumption and premise is false. Libraries, in the overwhelming majority of institutions, serve local communities, in the overwhelming majority of transactions. I've provided data to back my argument. You ... continue to hand-wave.

and only one type of media: books
We can doubt that the goal is to add value, and think it is simply to give some top-down structure that makes sense to the people using it. I admit that when I went into the stacks to find the book I was looking tor, browsing around on nearby shelves often led to additional good finds. These were topologically near. I think that would be the case for most good grouping schemes, though the choices may change.

Times have changes, the things that make sense have changed in various ways. At least it still organizes shelves.

"How is this distinct from organizing world information?"

Information has more dimensions than a bookshelf does?

There's no inherent need to arrange books by similarity, and there are numerous library systems that don't. (Most have "closed stacks", where patrons submit requests for materials.) The only requirement is that books be retrievable on request and can be returned to their assigned location when re-shelved.

A book can occupy only one physical space at one time. If it has an assigned shelf location for storage and retrieval, it can have only one such location.

The Dewey Decimal Classification assigns physical location by assigned subject, for better or worse. There's no essential reason to do this, and there are libraries which assign storage location by arbitrary identifiers, by size (this also tends to happen with DDS-based libraries, where there are specific "oversized" shelving sections, as well as storage for specific media types: maps, photographs, other graphic media (typically large-format), audio, video, software, and data.

For information storage, your storage subsystem (spinning rust, SSD, tape, cloud, CDROM / DVD archive, etched crystal, whaevs) handles the physical storage location element. A filesystem, if it exists, is already a layer of abstraction over that, and is already freed of many of the limitations of physical storage, though largely as a matter of convention and convenience we tend to act as if those still exist, e.g., a file exists in one and only one directory and that directories are hierarchically organised. Both are typical but not inherently necessary.

Tag-based classification drops yet another level of abstraction on top of the filesystem.

Problems with tags emerge in part from their very flexibility. It's possible to apply any given tag to any given work. Informal tagging systems, or "folksonomies", tend to be highly idiosyncratic, inconsistent, redundant, repetitous, and frequently break out in pain points with time.

Looking at this question myself, I see benefit in:

- Reasonably structured metadata. If you ever want to start a riot amongst librarians, declare your metadata schema as "reasonably structured". That said, author/creator, title, creation date(s), publisher, and some attempt at topic or subject classification will likely be useful. Checksums, size, and fingerprints (say, specfied ngram structures) might also be useful. See "Dublin Core" for an example which has both adherants and critics. For any possible set of metadata, you will all but certainly be able to find exceptions or inapplicability.

- "Search is identity". That is, any given set of tags or metadata might be considered a search, and any search will have one of three possible results: 0 matches (failure), 1 match (an identity search), or > 1 match (a result set). How many more than one has some reflection on how useful that result set is. In the same sense that 33 bits will identify any individual person on Earth, you'd need about 27 bits to identify any of the roughly 150 million published works. If your universe is the larger set of recorded but not published works, you'll need to expand your bits accordingly. (A recent estimate I've seen is that for every person on Earth, there's about 1.7 MB/s of data being recorded presently.)

- Names themselves are largely conventions. This might apply to any of the various names associated with a book: its title, its author, its publisher, the publication country or city, the date (and calendar system) associated with with publication, traditions, disciplines, educational institutions, references, etc., associated with it. All of these can and do change. (Quick: what are the names by which Plato, Avicenna, George Sand, Mark Twain, St. Petersburg, New York, Mumbai, and the Wilson School of Government are known by?) Good names are useful in that they are useful conventions and are commonly understood ...

All very good.

I have to admit that randomly browsing the stacks, flipping through the pages, has led to many serendipitous discoveries, that otherwise might not have occurred had I had to go through the trouble of requesting, waiting, and receiving books, subject to lending limits, etc. I miss doing that, actually. But at this point in my life, most public library stacks disappoint me, and the university library is an hour drive's away, though I do checkout books occasionally from it.

Shelf-browsing is a true joy, and I miss it as well. It's best supported at a quality academic library (though a local liberal arts or community college may afford its own rewards).

That said, I've learned the art of bibliographic search, based on references, citations, and less formal mentions, and find that quite fruitful.

There are also recommendations that turn up through some platforms (I'm partial to Z-Library's), which can be useful, though come with cautions. (Popularity is a poor proxy for either truth or value, though it lets you know what others may have read.)

Learning how to fruitfully use cataloguing systems is also tremendously useful. I make heavy use of Worldcat (https://www.worldcat.org/, DDG bang search !worldcat), Google Scholar, Microsoft's academic research tool when I remember it exists, Wikipedia (I read it for the references ;-), and keyword searches on Open Library, Project Gutenberg, and LibGen.

I'm finding myself relying far, far less on general web search than, say, 10--20 years ago. These aren't completely useless, but the trend is quite pronounced, over all major search engines (DDG is my default, though I'll use others on occasion).

The parent poster said exactly how it was different: "an average library has similar book-width for both topics."

Although of course what was really meant was that American libraries at the time of Thomas Dewey had similar book-width for both topics.

Of course you're right and I meant American Public libraries; I imagine Chabad-Lubavitch Library would probably lead to a different system. And the time I was referring was the time of Melvil Dewey, although I imagine not much would have changed by Thomas Dewey's time :)
damn, that is like the 6th time I have made that mistake (that I'm aware of).
> How is this distinct from organizing world information?

Any practical classification system starts with corpus at hand, and tries to organize that. Any idealistic classification system that aspires to be "complete" (at least in theory) starts with theoretically possible corpus, and tries to organize that.

For example, if you want to classify the pictures you have in your personal photo library, it would make sense to have e.g. a folder named "2020", for the pictures you've made that year. But it would not make sense to have a folder named "1900", as it's unlikely you made any photos then. This is a practical classification.

But if you want to classify all of the world's photos, you may need to start with a folder named "1826" to hold the View from the Window at Le Gras[1]. Or maybe earlier, for the paintings. That's a theoretical classification.

DDS is a practical classification, and as such, it started with the corpus at hand — whatever public libraries in the USA had at Dewey's time. This is how it's "distinct from organizing world information".

—————

[1]: It's not clear if the photo was taken in 1826 or 1827, so our theoretical classification would need to account for that, or for photos where the year is unknown, or estimated, etc.

I bet in Indian libraries it's the other way round. I don't like the trend of interpreting malice into everything nowadays.
One example of a data structure implementing faceted classification would be the multitree [0]. Unfortunately multitrees seem to receive far less support than 2 other data structures it intermediates: trees and DAGs.

k-d trees [1] are close but use cases seem to predominantly target data with inherently ordinal (rather than nominal) dimensions.

Further abstraction could lead to the knowledge graph [2] or graph databases.

In all cases, the availability of "low-code" tools (in the domain of single-user personal information management, at least) seems sparse. I have been looking for some time, but the search continues.

[0]: https://en.wikipedia.org/wiki/Multitree

[1]: https://en.wikipedia.org/wiki/K-d_tree

[2]: https://github.com/JeffreyBenjaminBrown/hode

Graph-based PKMS have recently exploded in popularity and sophistication. Athens Research (the OSS counterpart to Roam), and especially ObsidianMD (with its plugin ecosystem) are a couple examples of systems that might suit your purposes well.
rea.ch is a new Graph based PKMS that addresses some of the same issues so everything from File tagging to notes association as part of a second brain/zettelkasten schema.

[1] https://rea.ch/

Edit: I should also give a shout out to Treeview for Twitter which let's you select between different tree visualization of Tweets.

[2] https://treeview.ml

It's no substitute for a librarian, but I am interested in eventually trying out the Johnny.Decimal system [0] to build my own taxonomy based on what I use most often. (Basically choose 10 categories, and then subdivide those ten more times, by usage. These get numeric prefixes, to simplify navigation.) It's not for everyone, but the author says [1] he's used it for years.

[0] https://johnnydecimal.com/

[1] https://news.ycombinator.com/item?id=25412267

With enough discipline Johnny Decimal can work wonders, specially if you organize your work in the same way across different apps (say email, files, or productivity app)

Once you get the habit of using it, the most frequently used codes stick into your mind so it's effortless. And in case you don't remember it, there is a clear, fixed path to find the required resources.

Still, coming up with a taxonomy is hard and essential. Should I keep my home bills under home/invoices or invoices/home ? The answer does not matter, but you need to stick to it across all your areas of interest.

> Unfortunately, most of us do not have access to the services of a librarian to develop a taxonomy that corresponds to our own point of view then classify our files accordingly

Zettelkasten?

Emo Philips on subdivisions of religion:

Once I saw this guy on a bridge about to jump. I said, "Don't do it!" He said, "Nobody loves me." I said, "God loves you. Do you believe in God?"

He said, "Yes."

I said, "Are you a Christian or a Jew?"

He said, "A Christian."

I said, "Me, too! Protestant or Catholic?"

He said, "Protestant."

I said, "Me, too! What franchise?"

He said, "Baptist."

I said, "Me, too! Northern Baptist or Southern Baptist?"

He said, "Northern Baptist."

I said, "Me, too! Northern Conservative Baptist or Northern Liberal Baptist?"

He said, "Northern Conservative Baptist."

I said, "Me, too! Northern Conservative Baptist Great Lakes Region, or Northern Conservative Baptist Eastern Region?"

He said, "Northern Conservative Baptist Great Lakes Region."

I said, "Me, too! Northern Conservative†Baptist Great Lakes Region Council of 1879, or Northern Conservative Baptist Great Lakes Region Council of 1912?"

He said, "Northern Conservative Baptist Great Lakes Region Council of 1912."

I said, "Die, heretic!" And I pushed him over.

For those who don't know:

This is funny but for most Christians wildly incorrect (I'll add another funny one that used to be somewhat correct in my case towards the end.)

As a Christian I'll more or less want to save anyone who is in danger, no questions asked, as long as it doesn't put anyone else in danger. The reason is simple: besides being the obvious right thing to do as a human it also means we'll either have a good person living here for a while longer or a bad person will get another chance to change their ways (and have a very powerful reminder to do it).

I believe this is true for most of us.

As promised, an actual funny joke that used to hit home with me :

As someone enters heaven they go past multiple groups and the tour guide say: here are the righteous from this group and here are the righteous from that group until suddenly he tip toes past a door, saying: "here's <x> group and they think they are alone here".

(That said I'm still afraid many will be up for a rude awakening whatever group they feel they belong to if they aren't don't actually walk the walk.)

Captain Obvious suggests that Emo Philips was not joking about throwing anyone off the cliff, but about the very fact that political subdivisions in religions pretend to be about which moral values are more correct, instead of being dirty power games of self-proclaimed authorities covered up by thick layers of ideology. Our imaginary gods do not care either way and there is no evidence that we should care either.
skinkestek suggests that based on observation, not only in the case of religion but also in a number of other cases, captain Obvious is not visible to everyone, not even on HN.

You might think this is obvious but I think I have seen worse ideas taken "hook, line and sinker".

After all, common sense seems to be a rather scarce resource.

Edits: yes, to match the style better.

And no doubt if he'd been in India designing a system for an Indian library, there'd be more distinction between Hindu, Buddhist, and Sikh sects (nevermind those the not lumped together) and Christianity, especially denominations not usually found in India, would be the 'handful of afterthought headings', the ones with few books, and the books themselves doing more lumping together having less focus and depth on one niche.
itll only work with a round trip duplication, where files can be both and in multiple places.

this is more a filesystem deduplication problwm.

I ditched everything for a simple Zettelkasten in PlainVanillaVim all on a SdCard

EverythingIsAFile NoExtensions CamelCase

hit gf on a word/file/tag and enjoy freedom

:map gf :e <cfile><CR>

https://vimhelp.org/editing.txt.html#gf

sprinkle in RipGrep Fzf CtrlP as needed

This is tempting, at least for note taking. :)
I like to organize files in a similar way but use spaces in filenames. I find it a lot easier to read filenames that way, and in the shell, <tab> will add all the necessary quotes / backslashes.
Good ideas, but there are a few things wrong with this.

First, we forget that filesystems are not hierarchies, they are graphs, whether DAG's or not. [1]

Second, and this follows from the first, both tags and hierarchy are possible with filesystems as they currently are.

Here's how you do it:

1. Organize your files in the hierarchy you want them in.

2. Create a directory in a well-known place called `tags/` or whatever you want.

3. For every tag `<name>`, create a directory `tags/<name>/`

4. Hard-link all files you want to tag under each tag directory that apply.

5. For extra credit, create a soft link pointing to the same file, but with a well-known name.

This allows you to use the standard filesystem tools to get all files under a specific tag. For example,

    find tags/<name> -type f
(The find on my machine does not follow symbolic links and does not print them if you use the above command.)

If you want to find where the file is actually under the hierarchy, use

    find -L tags/ -xtype l
Having both hard and soft links means that 1) you cannot lose the actual file if it's moved in the hierarchy (the hard link will always refer to it), and 2) you can either find the file in the hierarchy from the tag or you know that the file has been moved in the hierarchy.

Of course, I'm no filesystem expert, so I probably got a few things wrong. I welcome smarter people to tell me how I am wrong.

[1]: https://lobste.rs/s/ydno8w/tree_structure_file_systems#c_njg...

> 2. Create a directory in a well-known place called `tags/` or whatever you want.

> 3. For every tag `<name>`, create a directory `tags/<name>/`

> 4. Hard-link all files you want to tag under each tag directory that apply.

Does this only give you one level of tags? (i.e you can't combine tags when exploring)

It does, unfortunately. But you probably could implement finding something with two tags with some command-line fu.

My first crack at it is this:

    find -L tags/tag1 tags/tag2 -xtype l | sort | uniq -d
I don't know if that would work (on mobile; can't test), but from reading the man pages, it seems like it would do the trick.
Replying again to give you a command that I've tested:

    find -L tags/tag1 tags/tag2 -xtype l | xargs readlink -f | sort | uniq -d
With this you can't easily search for files that have multiple tags, the whole point of tags is that you can use them to find set intersections.
See the comment I made to the sibling comment.

For a tl;dr, you can use the following to find files that have more than one tag:

    find -L tags/tag1 tags/tag2 -xtype l | sort | uniq -d
The lesson here is that being able to use command-line tools makes up for perceived limitations of the filesystem model.

Edit: After testing, I found the following works great:

    find -L tags/tag1 tags/tag2 -xtype l | xargs readlink -f | sort | uniq -d
The inability to define multi-tag searches (intersections) on Pocket is ... one of many gripes I have with that so-called tool.

Article roach motel is more like it. Though the roaches can escape via bitrot, and often do.

You forgot step 6. Convince everyone (and everything) else who has write access to the file system to follow suit.
Fair enough, although in my mind, I only care about tagging for my own files.
Tags are the lazy man's schema
Schemas are an ignorant / arrogant person's tagging system ;-)
One of the best uses of tags is to let a file effectively exist in multiple “folders”

For example I have folders of screenshots named after various shows and games, and I use tags to further organize the images based on their suitability for different “reactions” on online forums :)

So naturally I have hundreds of tags but macOS doesn’t seem to keep up with that many and after a certain point it feels like Apple have forgotten about tags and improving their integration into the system.

Or better idea. Use directed graphs. Directed graphs are strictly a superset of both tree and tag (set) functionality.

Tags (sets) can be thought as a special case of directed graph. You make the tag a node in the graph and you make files also nodes and have edge pointing in direction of the tag node.

You can then do graph queries to find files tagged in a certain way.

But graphs offers so much more.

Because they are superset of both trees and sets, you can use it to represent both, at the same time.

It is not very useful to have a lot of things tagged the same way because you end up with just a long list of things. Whereas in a graph you could say that you want to find objects from which you can reach certain tag node and all these objects can still have their own structure and even be part of multiple structures.

For many years I had this idea to build my PIM where I could make arbitrary nodes being anything that could let me connect anything to anything.

A node could be an email, a file, a link to external external website, a task, a contact, a reminder, etc.

And you could connect everything to anything and have, for example a project that has important emails attached to it, the email could have attached a reminder to respond and a file that you want to include in response, and a note.

You could browse this graph as a tree because locally it could be interpreted as a tree, you open the tree one level by finding all elements that pointing to the node.

How do you transform a digraph with cycles into a tree without? Seems perilous.
(comment deleted)
How do you traverse a symlink that points to one of its parent folders? How do you traverse a web of interlinked sites?

Somehow Linux, Linux software, web browsers etc. are already able to deal with directed graphs.

You can handwave cycles created by symlinks away by ignoring them. Full traversal is possible relying only on the tree.

If all you have is the digraph you have to rely on cycle detection. Transforming it into a hierarchy of depth requires snipping edges somewhere.

I'm just gently disputing the claim that a digraph can be mapped 1:1 to a hierarchical filesystem. I'm open to being wrong.

No, the intention is not to map it 1:1 to a hierarchical filesystem. My intention is to select a starting point, squint your eyes a little bit and then pretend it can be traversed from that point, the same you do when you search for a page on Wikipedia and then try to move around by clicking on links on pages.

On Wikipedia you can choose any starting article and probably traverse entire Wikipedia. Your traversal tree will be different depending on what you select as starting point but the end result will be the same -- you will have traversed entire Wikipedia. When you see an article you already saw -- you just skip it for the purpose of traversal.

Another way to imagine this: Windows Explorer

Select your starting article as root.

Then articles that are reachable directly from the root as first level nodes, then second level nodes are articles reachable from first level nodes, etc.

This is infinite depth tree because any cycle will cause an infinitely long branch.

But it is fine for a manual traversal (as a human you will notice you are repeating).

And if you are traversing automatically there are easy ways to detect you have already seen the node (just detect the node you are visiting has id that has already been registered somewhere else in the tree -- maybe put all ids in a hash set?)

---

I just figured out while trying to answer your question that the better description of what I would like to achieve would be "hyperlinked filesystem" except that hyperlinks also carry additional information about the link itself. In a filesystem there is only one type of link (parent/child folder/file relationship). In a hyperlinked filesystem you would have possibility of many types of relationships.

On a normal filesystem Emacs could create a file with a tilde appended to its name to express it is backup of a file without tilde.

On a hyperlinked filesystem Emacs could create an explicit link between the files with a suitable role.

---

A filesystem like that would probably need multiple other ways to locate the files but it does not have to bee a tree-based structure. A tree-based structure would require the user to find a place for the file which misses the point of the filesystem (being free from having to find a location for the file). For example, additionally to graph based searches you should be able to search for properties including full text search on properties like names, descriptions, etc.

Knowledge classification is not directed.

I'm not sure entirely how to describe it, though "probabalistically associative" is a phrase that comes to mind.

It looks like a digraph in many local regions, but overall is not.

It is not knowledge classification. It is association (like this PDF file is associated with this project).

But association can be used for classification (this PDF file is associated also with THAT topic). Which is exactly my point.

Hierarchical filesystems can be used for classification (create folders for classes, put things in right folders). But the issue is that the user has to perform classification to even be able to store the file and you can only put the file in one class so if you do that poorly you will have hard time finding it later (a condition which I call disorder).

Association lets you overcome that problem by allowing you to associate the item with multiple classes.

If your aim is to be able to find it later it is better to put the item in too many classes. A filesystem that only allows you to put the item in one class requires you to make a good decision immediately.

Additionally, there is low cost of making a mistake when adding another association but there is comparatively larger cost of changing the classification by putting the file in another folder.

You're using the case of some directed relationships to argue for exclusively directed relationships. That is a false generalisation. Using a directed graph (exclusively) requires that classification assocations be strictly directed.

That's simply not the case. It can appear that way in certain instances --- an author writes a book, a book doesn't write an author. But books influence authors, and multiple authors (as contemporaries) can influence one another. Topical classifications may descend through one of several directions: a history of a technology developed in a place by a specific person might have points of entry by date, location, biography, technology, application(s), or consequences. There's no single "home" for that concept, but a web (a non-directed, potentially cyclic) graph with multiple relationships, many bidirectional.

That leaves you with a few options:

- You can abandon the directed graph and utilise an indexing and search schema which more accurately describes the relationships.

- You can abandon strict accuracy and settle on a useful directed graph which imposes an arbitrary (and incorrect) hierarchy over the subject. Where physical storage is based on topicality, the requirement of a single locality imposes this requirement.

- You can find an alternate basis for defining location, and conceptually map that by other means. Here a key issue is (as I've described in several earlier comments) that position alone is neither a guide to the content (adjacent documents may be utterly unrelated), the researcher (there is no streightforward exploration path to a specific record or concept), nor the curator (topics must be specifically assigned and aren't inherent or evident by position).

In declaring that "it is not about knowledge classification", you've attempted to change the scope of the discussion. Even in the example you give, the case falls apart. A project may be associated with multiple PDFs, and a PDF may be associated with multiple projects. How do you describe that set of relations in a directed graph?

Are you assuming your graph is acyclic?

> Are you assuming your graph is acyclic?

No. I made a small PoC and one of the things I tried to learn was if it is possible to basically disallow creating cycles (because they are a headache). I found that preventing cycles completely was irritating to me as a user as it would occasionally prevent me from making a change and require to fix the structure somewhere else before I could do whatever I wanted to accomplish in the first place.

OK, I can agree to that.

Now for directed:

Is a work an attribute of an author?

Or is an author an attribute of a work?

Are these seperate relationships? Because it seems to me they're not.

Is the work-author relationship inherently directed or not? Because it seems to me you're claiming it is. I ... would disagree.

(We could pick other relations, that's a fairly simple, straightforward, and common case.)

Let me explain a little bit different way.

My first run in with the idea was when I started using Ultra Recall for GTD, many years ago.

https://www.kinook.com/UltraRecall/Manual/multilinking.png

Ultra Recal is an app for managing personal information that uses SQLite internally to store a tree of objects.

Look at Data Explorer. It has various types of nodes, you can define new types of nodes, and there is no restriction on how these nodes can be nested other than they form a tree.

I used Ultra Recall for couple of years for my personal workflow.

In a normal hierarchical filesystem you have this restriction that files are placed in folders and that's about it. You can have multiple types of files but folders are just bags for files with not much additional data (other than folder name) and you can't have files nested below other files.

In Ultra Recall every object regardless of type accepts child objects.

I found this to be very powerful, for example, I could have an email but then write a note being a child object of the email. Or I could create an object that was an actual working reminder. Then I could move that email to be nested under some task object and Ultra Recall had facility called "saved search" which allowed you to define a search for example for all projects that don't have next actions under them or all tasks that have deadline within next week.

Some other types of nodes are actual files -- you can put a webpage or a document and these become just part of the tree.

One problem with this is that when you try to add an object you need to figure out a location. As Ultra Recall is a tree (there is always one parent), when you are adding items you need to decide location (ie. what the parent is) even when this is not strictly meaningful or when there are multiple potential candidates.

For example, sometimes you have something you have vague idea you want to preserve but you just don't have time now to decide. Or an item could potentially be useful for multiple projects.

But sometimes you can be sloppy with this. For example, Ultra Recall offers full text search so you are free to just dump some of the stuff in a folder and forget. When you need it you just run a search for any part of the document or its properties (tags) and it gets brought up.

So I created couple of "dump" folders where I could just throw stuff in (like "read later").

I started writing keywords at the top of documents and I could then more or less ignore when the document was placed if I could not find a good location for it. Deciding where to put stuff is a chore when you create a lot of documents and rely of classification to find them later.

But this only solves the case when you have no immediate parent candidate. What if there are multiple parents that you would like to use?

For example, the parents are various projects and the child is an email that is related to those multiple projects. I would like to be able to have multiple parents (projects) to which the item (email) is attached.

So I was toying with the idea of making a little better Ultra Recall by relaxing the requirement that an item has only a single parent node. In effect, this creates a graph where any item can have multiple incoming relations (children) and multiple outgoing relations (parents).

Just commenting to note that I'm finding this interesting and provocative. Not necessarily convincing, though I'm thinking my way through questions and concerns.

I'll throw one thought out just for grins: why do we bother with documents and records at all, and what is the value in going through old records.

(I'm asking far less because I doubt any value, somewhat more because I've been put this question (by someone whose sanity and motives I very much doubt, and for whom no response seems sufficient), and because I think it nudges at some very-frequently unquestioned assumptions and motives about this whole endeavour.)

That said, I'll try to return to and respond to your comments more directly.

> why do we bother with documents and records at all

We bother because from a developers' perspective, if you are interested in interoperability with other software, it is convenient to store information in files that can be passed by name to another piece of software.

Nowadays we have a lot of webapps that do not store information in files (the databases behind them use files but this is not important for the user). If you notice, interoperability is pretty bad and has to be developed separately, every single time for every single use case. You can't take your "facebook file" and grep it for the contacts you are interested in or pass it to some other program. You can't make a backup by creating the copy of the file, and so on.

But I digress.

The issue isn't about files being a problem (I don't think they are). The problem is about organizing them. There simply isn't any good organization idea implemented in practice. People say files are too hard for normal users but what they really mean is that users are lost in a normal filesystem or they are going to be lost after they have created enough files without being super tidy.

I would be glad if files themselves vanished completely from the users' view and only stayed there as an intermediate storage layer.

Thanks for that, though I suspect developers aren't the only user-community for documents ;-)

If I can paraphrase your statement about files: they solve a technical problem in computer space, but don't reflect how people want to and/or need to access information.

I'm reminded somewhat of mainframe DASD storage, which has a few characteristics:

- A largely flat directory structure. There can be directory equivalents, but to a limited depth (1 or 3 maximum IIRC, possibly depending on OS release).

- Structured files. That is, the concept of a "flat file" or a "binary file" doesn't exist (or is rarely used), rather files are specifically structured, into records (~= lines or rows) and fields (~= individual values), with a record type indicator as the first few bytes of each record. A file could contain (and most often did) multiple different record types, as a hierarchical data file.

- Specific programmes to read each file type.

(At one point I worked in writing code to read data files, including IBM mainframe files. That was many moons ago and much of the work was not on IBM mainframes themselves, though some was. I've suppressed much of the trauma....)

These days we tend to use an RDMBS database structured as rectangular tables with columns and rows (also invented at IBM, and available on mainframes, though not often part of my previous life).

Funny thing: SQL was originally pitched as a query language that could be taught to secretaries and administrative staff to directly run queries against databases. Either admin staff were much more brilliant then, or that was an ambitious vision....

Or ... we have various structured data formats that aren't rectangular: XML, JSON, HTML itself, amongst others. These have a structure and can be picked apart, though they're still fairly complex.

What I've seen over a career of 30+ years is that the vision of some single universal data format keeps getting pitched ... and keeps not materialising. Because Reasons a specific application has its own needs, and/or the "standard" is so complex that it is never implemented the same way twice. Data interchange always needs to be specifically structured and engineered.

For mostly-textual information, which is where I think of tagged systems being most appropriate, the internal structure of documents is ... fairly loose. Metadata + bag of bits, mostly ASCII / Unicode. But that still leaves us with the problem of sorting out what's where and how to access it.

I'd argue that most present filesystems are inadequate to the task of and by themselves, though they might be extended. An interesting and fairly simple example is the maildir format for storing email. It lives on a standard filesystem, and its naming convention is opaque (email message IDs). The file structure itself, based off RFC 822/2822, includes a set of defined and structured fields (headers) providing metadata. A special access program, a mail reader, provides access to the mailbox(es), though other tools can provide more programmatic process. Principle organisation is by data, though other metadata aspects can be used.

As a rough proxy of what a document store might look like ... this isn't a completely bad start, and it might offer guidance to how a more generalised document-oriented filesystem might be structured.

Backing up a bit myself, I've been trying to establish two related, but distinct points:

- There is not a single unambiguous or consistent hierarchical structure to topical knowledge overall. This is a trap numerous organisational attempts, dating to Aristotle, have fallen into. (The history and attempts themselves are fascinating, for those into that sort of thing.) That is, the hierarchy as a whole is not directed.

- An attempt at such a mapping is frequently made where a work or works (frequently: encyclopedias, in the former case, libraries in the latter) must be arranged such that there is a single canonical ordinal or spatial organisation. There are other alternatives, such as alphabetic ordering used in many dictionaries and encyclopedias. This works where the alphabet involved is reasonably compact, has a definitive single collation order, and entries themselves are at least reasonably distributed across the indexing scheme (e.g., there's not a single character with an overwhelming number of topics). It's effectively a hash using the first character under the writing system.

- Even in the far more relaxed case of a defined relationship (RDF triples are frequently used in bibliographic classification), there are cases of relations which are not themselves directed. E.g., authorship is a relationship which exists between one or more persons and a work. A work has an author, an author has works. Similarly, two people are "in" a relationship. Remove authorship or relationship, and all the relations are removed. (Though there may be unrequited love, unrequited authorship is less often observed.) Though we might impute a relationship based on some other: if work has author, then the relationship author -> work can be imputed. This despite the fact that it is the author who volitionally created the work in the first place.... It's ... confusing.

Tagging is a form of RDF triple. Entity has tag. That gives us object and object, but not much by way of predicate, other than "has".

Your Ultra Recall example doesn't do much for me as I'm not familiar with it and can find little information online other than a CNET download link. That said, I'm vaguely familiar with knowledge management systems. UR seems vaguely similar to Hypercard or a Wiki, though with the significant distinction in your description that UR apparently has an explicit parent-child relationship between nodes, whereas in a Wiki (and AFAIU Hypercard), relationships are merely as peers. As you note, this ... can lead to awkwardness and ambiguity, as well as imposing a cognitive load when creating a new node.

OTOH, there are entities which have a specified order. The collection of characters within this post would have much less utility as an unordered (or differently-ordered) set. Pages and chapters in a book, volumes or episodes in a series, scenes in a film, slides in a presentation ... without a specific order, much value is lost.

The alternative I favour is for some metadata to be inherent or intrinsic, whilst other metadata is specifically assigned, created, or evolves.

Intrinsic metadata might include: contents, creation (or aquisition/curation) date, author(s) (if known, whcih is generally the case for works created within a given management system). In general, time may well be the most universal initial placement mechanism, that is, thinking of the system as a filesystem, date-based access is a principle access method.

Pretty much all other metadata is either explicitly assigned or occurs through interactions. A work might be linked from another. It could have a specific title and subject(s) assigned. Translations, summaries, and reviews might be created from it. It might be cited, or cite other works. That's all metadata, but it isn't endogenously entrinsic to the work...

I find that using Everything search (https://www.voidtools.com/) makes me use the filesystem more like a tagging system. I still name files and directories meaningfully, but I don't worry about the hierarchy at all. Then when I want to get something, I just search (parts of) the terms I want and see the matching paths instantly.

Using the filesystem hierarchically now feels painfully slow and awkward.

I do this with fd and ripgrep, which also lets me do full-text search through the files themselves. My filesystem has become much flatter and coarser-grained; just a few very large categories.
I remember trying to use tags to tag my media collection a decade ago and miserably failing