We ran the Project Reality League, the only clan competition site for the Project Reality mod for BF2. It focused on 6v6 infantry clan matches on the smaller infantry versions of the maps. Earlier versions of PR played like a hardcore mode version of BF2 - tactical realism and deadly weapons - a little bit like what a more focused and less random BF3 cqb style game would be like. It was a bit like a more open scale True Combat Elite, or Insurgency, with occasional vehicles. We contributed code and map layout designs to the mod for this.
Even though that segment of the game was excellent, small scale clan battles was never the focus of the PR mod, and by version 0.7 it had changed into a boring military sim. By various mechanisms, it removed FPS gaming skill advantage and turned it into a role playing simulator type experience. So that obviously put an end to the PRL, but it was fun while it lasted.
Here's the newest and oldest snapshots I have of the standings.