It is the initials of one of the Latin names this poster previously used; unfortunately I can't remember what it was. The poster changes his name every few months but is easily recognized under whatever name he uses. When I asked him after one change the reason, he wrote that it was like changing his jersey and he does it according to his mood. I think it is best to totally ignore him but have occasionally succumbed to the temptation to question him. A few people try to bait him and when he takes the bait (he didn't this time), lengthy and annoying chains sometimes result since the baiting writers then take his bait and he likes to try for the last word.