Would they be auto generated from a preset list that we’d choose when creating the threads or the users would type their own each time?
So the way it worked on OPF when we eventually got prefixes (I don't know why Owl didn't implement them because they're incredibly useful) is that an admin makes a pre-defined list (so for example, the tag "Manga Spoilers" for threads that included manga spoilers). They didn't take that long to make either, because there aren't really many that we actually needed (I think we had about ten in the end, and we'd need even less here since we don't post scans or spoiler threads any more). I don't know how it would work on here though - at the very least, it's not built into VCC like it was for OPF so that'd be a project for rio.
As for keywords, the user decides those.
Rohan I'd be all for this, especially the prefixes.