The privilegium fori (Latin for "privilege of the (legal) forum") is a generic term for legal privileges to be tried in a particular court or type of court of law.
Typically, it is an application of the principle of trial by one's peers, either by such a jury or at least by a specific court from that social segment, such as a soldier by a court martial, a cleric by an ecclesiastical court.
Privilegium fori used to be one of the ecclesiastical privileges in the canon law of the Catholic Church: a member of the clergy received a special tribunal in civil and criminal causes before an ecclesiastical judge.
References
Privilegium fori Wikipedia(Text) CC BY-SA