Okay, I've been working on this since yesterday, reviewing the whole stuff for commit, and then it occurred to me...
What would you prefer, now that the "unread posts in this board" thing is removed?
Would you prefer the board status icon to tell you:
1- "This board's latest post is 1 day/1 week/1 month/1 year/+ old" (current solution)
2- "This board's latest post was made after your last visit" (it'll stay turned on until you log out or just leave the forum for 15+ minutes)
3- "This board's latest post was made after your last post" (it'll stay turned on until you post anywhere again)
4- Give a user option to choose between these..?? (Overkill, probably!)
(1) has the advantage of being already written, ah ah. It also encourages you to post in old forums. The main drawback is that the various visual "levels" can be confusing. Which can, of course, be "fixed" by reducing to a couple of levels (new posts today, no new posts today.)
(2) has the advantage of using last_login data, which is free. Or id_msg_last_visit, also free, dunno which would be best for now. Although, if I don't use this, it means I can remove the id_msg_last_visit column from the members table, because I can't think of a good reason to keep it. (It was used in SMF to determine unread posts "for this session", but Pete removed that, although he never removed that item from the table.)
(3) would require recording your message ID to the members table everytime you post something. That's an extra query per post action, although maybe it's already done, but I don't know where.
Please discuss!