I guess the rule was made so no one would feel left out or uncomfortable in the guild chat.
I think it’s mostly because of their privacy policies— not only in the game but within the guild also— in Korea calling someone by “hyung” (or oppa, eonni/noona) literally means “older brother/sister” and is used to call other people very close to you, and by calling him hyung in public, not only that shows that they may be close to each other irl, but they also breaks the rules of only using the formal form ( with the ㅂ니다/습니다), plus only Jigu knows that MC (I forgot his name-) is neutaaa..idk if that andwered your question but yeah
omg YEAHHHH i forgot there was a guild rule against it my bad it’s been so long since the earlier the chapters
I still don’t get the problem with the others knowing he calls him “Hyung” though? They’re the only ones who know each other irl (it’s another thing that yeowoon is oblivious as hell to that) - is it really that big of a deal? Like they were even a couple twice in the game