Put their type in their signature?!!
I mean, this is a socionics forum, everyone should therefore have their type in their signature (or at least their most probable type, if their type is disputed). The whole point of this forum is to explore the 16 types, right? Why would someone not have their type in their sig? Following a thread is frustrating when people don't display their type, and I find myself often not even reading posts by people who don't display their type (unless they're one of the few people who's type I know from following a "what's my type?" thread, even then, it's nice to be reminded with every post).