Treaty of Ectair

The Treaty of Ectair was an agreement signed by the United Federation of Planets and the Romulan Star Empire in 2274 as a result of an encounter at the planet Ectair a year earlier.

The treaty allowed the Romulans access to non-Federation worlds along the frontier provided they did not cross the Romulan Neutral Zone or approach within five light-years of any Federation planet. (FASA RPG: Star Trek IV Sourcebook Update).