In the bit which shows you who's online, some of the posters' names have a + after them. Is there any reason for this? They're not mods, or something are they?

Most users ever online was 187, 01-03-2006 at 01:58 PM.
benbaaa, aging one, Airportwo, attaboy, Begbie, buadhai, dirtydog, DrAndy, friscofrankie+, Georgie-Porgie, Gerbil, Goddess of Whatever+, hunter, in4zip, lom, Marmite the Dog+, mrsquirrel, obsidian, otherstuff1957, ozman, reinvented, Sir Burr, spliff, The Gentleman Scamp
In this list, it's frisco, GoW and Marmers