When you have between 0-25 posts your rank is a Dungeon Delver and you get a PHB icon. Between 26-50 posts gives you the rank of Dweller In the Ruins (PHB and DMG), between 51-75 you get the rank of Denizen of the Underhalls (PHB, DMG, MM), and from 76 post and above, you are a Citizen of Undermountain (PHB, DMG, MM, BOA)!
Administrators and developers use the icons at the bottom of that chart, and always have 4 images as show. They're pretty much self explanatory. We somtimes add special ranks for people doing special projects for the site.
