i thought you could always rp knowing the guild because of a guild badge or marking
Unless they were a secret guild, that the members didn't want to let Outsiders know they were part of it. But if it was that case, then you would make the guild secret to hide it from showing.
Or maybe if a member of a guild is under cover. So they hide thier guild marking/badge from site.
The way I RP it, is I take a look at thier description. If it states in thier that they have on a guild badge/marking whatever, then my character knows they are in said guild. If no mention to this, then he doesn't know. Unless they are famous, like Karyuu. Then even if they have never met, my character still knows, through word of mouth from other players. Reputation preceding ones self so to say.