Reasonable Person Principle is the rule which you must abide by when accessing this network. Put differently, following the Principle is your obligation to your fellow community members.
The Principle was borrowed from Carnegie Mellon University, who use it as the governing principle for access to their computer systems; since it works for a whole University, we hope it will work for an IRC network with a few thousand participants. So far, results have been positive.
From Carnegie Mellon University's own explanation of the Principle:
Reasonable people think about their use of these facilities, and the needs of others, and adjust their behavior to meet the goals of a common good for the community, i.e., expressing what you want to say, but accepting and accommodating the needs of others.