<aside> is in HTML5.
<abbr> would be incorrect for this usage. You could, perhaps, stretch the use case of the "i" element (not "em"), though a simple span would probably be the way to go.
<abbr> would be incorrect for this usage. You could, perhaps, stretch the use case of the "i" element (not "em"), though a simple span would probably be the way to go.
If that isn't proper, I hope there's an <aside> tag in some upcoming version of HTML; it's at about the same "semantic" level as <q>.