And..I suggest building UPON that idea;
Keep a <2 minute? 3 minute? 5 too much maybe> recent list of players in a table and the pertinent info you'd need to warn them while not connected.
Show those in a sub/side menu when using the GUI menu, or from console, a text list.
awarn_recent - with no input, prints out console text of names, with name and some id#, with higher number being most time left.
awarn_recent <id#> <reason> would warn/add warning to that players stored info.
If a player rejoined, removed from 'recent' table. As players leave, added to table, to be removed later after timer expiration.
I imagine something like
] awarn_recent
01 JamminR
02 Megiddo
03 MrPresident
Use awarn_recent id# <reason> to warn player.
] awarn_recent 01 Giving awesome ideas that would require full rewrite to fellow developers
JamminR has been warned!