I noticed this when I took a dive in the search engine. Under some user’s name, there was the label ‘obvious imposter’, instead of ‘member’, ‘moderator’, etc… I gotta admit, I’m pretty curious about this. What, pray tell, is an ‘obvious imposter’? I assume it’s a bad thing, so how do I avoid becoming one?
As I recall, a while back, some person or persons were making a nuisance of themselves by signing up with usernames that were indistinguishable from other names currently in use. They did this by exploiting an interesting little feature which I won’t detail because I can’t remember if that particualar bug was fixed or not.
Anyway, the appearance of what were (apparently) members in good standing making, shall we say, out-of-character comments was confusing, to say the least. Rather than add to the confusion by labelling the imposters “banned” (as they eventually were), the administration labelled them as “obvious imposters.”
Yes, the bug was fixed. It involved the imposters registering names that were the same as already registered names with the exception of a space before the first character. For example, ’ Derleth’ to impersonate me. This would show up as merely ‘Derleth’, the board having eaten the initial whitespace with a nice sauce. 
Anyway, I don’t think you can register a username with initial whitespace anymore, so the problem is solved.
Wow! Isn’t that exactly what Ender did in Ender’s Game? Talk about life imitating art!
Lovely book.