Number of posts AFAIK. I think there's a list of ranks and number of posts needed somewhere.
1-20 Merely Curious
21-50 Beginner
51-70 Hobbyist
71-150 Too much caffeine
151-500 Technoid
501-1000 Cult Member
1001-2000 Defender of the Faith
2001-3000 Kindred of Babble-on
3001-4000 Desperately needs a life
4001-5000 Energizer Bunny of Babble
5001+ Guru Meditator
Given the age of the forum, we might need some more
As I recall, In the XOOPS days, once you hit 10,000 posts, your rank disappeared all together.
