In igl.net it is described as 'True Swiss Sistem'. Wikipedia describes a bit more - http://en.wikipedia.org/wiki/Swiss_system .
I mean if there are 7 round tournament then every player plays 7 rounds with players with similiar streght (score), not laike in round robin tournament where all play all (http://en.wikipedia.org/wiki/Round-robin_tournament).
Here at RHP in many tournaments are 5 and more rounds. If it would be 7 it would be more interesting and not much longer, but comparing the largest tournaments even less rounds.