HN feed filter/category idea

I love the HN feed... but there are some topics Im not interested in at all, and seeing that it is a large feed with lots of content, I would like to filter out the stuff Im not interested in.

Could we start a convention of putting [catergory] in the titles ?

eg

Cool new proof of Pythagoras theorem [MATH]

Bitcoin is a fools game [BITCOIN]

etc

This way everyone still gets the full feed and those who want to filter can...

What do you guys think?