As most may know, a change in early July to the Steam server browser for Source engine mods has been changed so mods were no longer showing up in server browser queries.
We have verified the fix which all HL2CTF 2.1 server admins should apply to their servers.
Please update your server.cfg with the following variable:
After updating your server.cfg, restart your server and it should show up in the server browser. We hope that players who can contact server administrators will pass this along so all of the HL2CTF servers will return in the server browser for the mod.