Continuing the discussion from UserNameSuggester suggests names with trailing underscores:
But can you mention with
@ a username ending in
_? With Discourse 1.4.1 it doesn’t seem to work, or at least the preview doesn’t format the attempted mention as a mention. If then you use
@username_, @another_user (without a space between underscore and comma, and with another underscore-containing username afterwards), things work even less well — the text between underscores is formatted in italic (because Markdown parsing triggers), and both mentions break. This bug is triggered when expanding
@group, with a group containing such usernames; the usernames happen to be output in that bug-triggering order.