Detect and distinguish "topic type" (video, PDF, etc.)
I think this will probably be separate from tagging, but could be very useful for searching/filtering/etc.
Suggested/discussed in Unofficial Weekly Discussion #2:
https://tildes.net/~tildes/gc7/unofficial_weekly_discussion_2_topic_tag_system_brainstorming_session#comment-3qb9
To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information