GetNoRumors

As of Skyrim 1.8.151, this condition function is not used in Skyrim or any of its official plug-ins.

This function returns 1 if it's run on an actor and that actor has been flagged as having no rumors; it returns 0 otherwise. The only way to flag an actor as having no rumors is via SetNoRumors, a console command that exists as a leftover from older games' script engine.