Temporal Accord
The Temporal Accord, also known as the Temporal Accords, was an interstellar treaty signed after the development of time travel, prohibiting the use of the technology for changing history. It was in force by 2769. The Accord permitted time travel only for the purpose of scientific research, and set forth rules and procedures as to how to do so without contaminating the timeline.

During the 30th century, the United Federation of Planets became involved in the Temporal War and spent most of the 30th century fighting to uphold the temporal accords. ()

Certain groups who held time travel technology chose to ignore those rules, and actively attempted to alter history to suit their own ends. These factions were opposed by temporal agents in the 31st century, in a conflict known as the Temporal Cold War. ()

By the 32nd century, all forms of time travel were banned. 

Part of the Temporal Accord was the Interdimensional Displacement Restriction. ()

de:Temporales Abkommen
ja:時間協定
nl:Tijdelijke akkoord
uk:Темпоральна угода
Accord
Treaties