Ask HN: Why prohibit spaces in usernames?

11 points by PhasmaFelis ↗ HN
My preferred user name has a space in it. In the early days of the Web, when you tried to create an account somewhere and it wouldn't let you use spaces, it meant that their user management system was so rickety that it thought spaces were field separators, and had to be protected from itself. By the mid-2000s, most sites had sorted themselves out and allowed spaces.

In the past few years, this seems to have reversed itself. More and more major, professional sites--Hacker News included--are again prohibiting a character found in pretty much every human name. Some sites don't even have an explanatory error message--you try to create an account, and it says "Your username is invalid" and leaves it to you to figure out why. Fiverr doesn't even do that, it just put a red border around the text entry field and glares at you.

Is there some solid technical reason for this, or is it so kind of giant contagious mental block? The only thing I can think of is wanting to parse usernames out of posts Twitter-style ("@PhasmaFelis"), which I've seen in a few forums, but most sites with this issue have no such feature.

6 comments

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Spaces can also cause problems if you want to generate a URL for a username (requires inserting '%20') or if you want to generate an e-mail address for them.

Also, spaces (like dashes and underscores) make it easier to create similarly confusing usernames (i.e. "maryjane" and "mary jane")

The second argument does not hold: maryjane and mаryjаne are similar but are different sequences of bytes.

The other issue with spaces is that you cannot easily tell how many there are. For example: "Johnny Appleseed" vs "Johnny Appleseed".

BTW, are there any languages/cultures in which the name structure dictates spaces before/after the name or the number of spaces between words in the name?

Humans don't parse things byte by byte, his argument is perfectly valid. Yuo cna stlil raed tihs cnat yuo?
The second argument does not hold: maryjane and mаryjаne are similar but are different sequences of bytes.

You're nit-picking with that attempt at an argument. If I'm a moderator of a large forum and my user name is "MaryJane", is the community made better when a "Mary Jane" joins? Obviously not - there would be confusion as to who the mod is (regardless of icons/colors/other text used to display the true mod). In marketing speak, "It dilutes the brand".

Let me switch this around and ask why have user names at all?

Most sites these days allow you to log in with your email address as your "username". At that point you should be able to choose whatever you want as your display name.

The only problem with getting rid of the username completely is that the username is by definition a unique string, while display names or real names can be the same, so you have an issue with deduplication of display names. You can easily end up with a system like YouTube comments where people troll by using the same name and avatar as others to impersonate them.

One of the biggest disadvantage is telling your username verbally. My name is Leonardo<Space>De<space>Vinci v/s LeonardoDEVinci