You can actually add in more specific search terms, since if you're looking for a two-word guild name, like;
Azure Knights
doinng /who Azure Knights would look for anyone in the guild Azure named "Knights". You can instead do;
/who g-"Azure Knights"
and it will return everyone in the guild Azure Knights. There's also the n- (Name), z- (Zone) and there's a level one as well but I can't remember the code for it.