Pentad and the Hexad.
Neuronphaser has two articles so far, check out The Circle a power group made up of NPCs closely associated with Mordenkainen and the Circle of Eight. and then read about The Guild, which is no less than the well-organized thieves guild in the Free City of Greyhawk.
I am looking forward to neuronphaser's next few articles set in Greyhawk. Kudos!