In the Roman Catholic Church, incardination refers to the situation of a member of the clergy being placed under the jurisdiction of a particular bishop or other religious superior. Its antonym, excardination, denotes that a member of the clergy has been freed from one jurisdiction and is transferred to another.
Both terms are derived from the Latin cardo (pivot, socket, or hinge), from which the word cardinal is also derived - hence the Latin verbs incardinare (to hang on a hinge or fix) and excardinare (to unhinge or set free).
The purpose of incardination is to ensure that no cleric, whether deacon or priest, is "freelance," without a clear ecclesiastical superior to whom he is responsible.
In the Church, a man is incardinated as the clerical subject of a diocesan bishop or his equivalent (a vicar apostolic, territorial abbot, territorial prelate, superior of a personal prelature, etc.) or of a religious order upon ordination to the diaconate: within the ordination ceremony prior to the actual sacrament of Holy Orders itself, the man places himself under a promise of obedience to his bishop or other superior within a particular church, or makes an acknowledgment of a pre-existing vow of obedience to a prior, abbot or other superior in a religious order.
Once incardinated, the cleric remains the subject of these same superiors even when ordained a priest. This incardination does not cease until the moment when that cleric is incardinated as a subject of another superior. An excardination from one diocese, for instance, does not become effective until the moment of incardination to another, so there is no gap during which the clergyman is not clearly answerable to a definitely determined superior. Incardination is dealt with in Canons 265-272 of the Code of Canon Law.