I see a lot of times people calling out a guild, or saying it's not enough to say a keep is under attack, you also have to say which guild.
I've never seen someone's guild when targeting them. I don't even see an option for it in Options. And they can have up to five guilds anyway so how do you even call out a guild?
I've actually wondered this for years lol. Never cared much but now I'm wondering how people can see an enemy's guild in Cyrodiil?