tool to add comments to author/creator names?

[sylvaine]

I seem to remember DW or LJ having - either natively or with an add-on - a way of adding private notes to a person's username which would pop up in the hover menu, where you could put, well, whatever comments you wanted to about the person, but which I tended to see people use for names, pronouns, usernames elsewhere, where they knew the person from, etc. Is there a tool of some kind that would let me do this on AO3? I would prefer it not be a hover menu, since those are difficult on mobile, and if they could be synced between devices in some way that would be even better, but really I'd be happy if this exists at all in any way.

Alternatively, does anyone know if this kind of thing is even technically possible to do?