Board Thread:Warhammer 40k General Discussion/@comment-1302704-20140317042239/@comment-3055683-20140317042715

IMO, I believe the symbol may represent part of the Eight-Fold path of the Chaos Star commonly utilized by the Forces of Chaos. The flames probably represent fire and destruction -- the ultimate goal of annihilating the Imperium and all followers of the "Corpse-Emperor".