[WhiteDragon]

I tried as well with no luck, both serverside and clientside. I also searched the wiki for onNickChanges, with no results.
There is no mention of it in graal -listscriptfunctions either, but that doesn't list events at all, so no surprises there I guess.

Maybe it just somehow got added into /scripthelp without the event actually being triggered, or maybe it's just not catchable.