AoSHQ Tags
I see stupid question was answered thoroughly.
Commenters survival guide - tags
i : italics
b : boldface
u : underline
s : strike-out
Safarisino, those are the only tags commenters have.
Well, there's also
a : link to a site
as well as video and image embeds.
But you can only see or use those with the Platinum-Plus subscription.