Add two serversettings like "sv_info1" and "sv_info2".
A serveradmin can write some text there and it will be shown in the low left corner (unused place; red in the picture) on the hud from each client.
The text in the picture, could be made with this for example:
sv_info1 "[OTB] Clan"
sv_info2 "Since 2005"
So there is one setting for each line.
I made the text in the picture with this code in the cl_scrn.c, but its better to have a serversetting, where each admin can make his own message. I don't know, how to do that.
re.DrawString(viddef.width/16-1*hudscale, viddef.height-20*hudscale,"[OTB] Clan");
re.DrawString(viddef.width/16-1*hudscale, viddef.height-10*hudscale,"Since 2005");