From BoyWiki

Cog commonly refers to administrators on BoyChat, and by extension, the Free Spirits family of forums. The first cogs were instated by Camper to assist in the administration of BoyChat, whose activity had rapidly grown during its first few years.

The cogs are tasked with the interpretation and enforcement of BoyChat's Seven Rules. They are ultimately responsible for maintaining the legality and civility of the forum as directed by the rules of Free Spirits for all sites.

Each cog has access to tools that allow him to edit, delete, or move posts, to add or remove registered users, to ban or unban posters, and otherwise to intervene when necessary to keep the board running.

cog n.
A subordinate member of an organization who performs necessary but usually minor or routine functions. (The Free Online Dictionary)

Cog often refers to gears or spokes that give support and enable motion. This name was chosen by Camper when the team of volunteers was first assembled.