When a Latin Rite Catholic is preparing to marry an Eastern Church Catholic, the ordinary of the Easter Catholic should be consulted. The Diocese of San Angelo Tribunal may assist if needed.
According to the Eastern Church Code, the couple must marry before the pastor of the groom (CCEO, no. 831).
A priest must preside (CCEO, no. 828).
Latin Rite Bishops cannot dispense the Eastern Church Catholic even if in his territory (CCEO, no. 835).
When a Latin Rite Catholic is preparing to marry an Orthodox Christian, the Orthodox Christian's ordinary should be consulted.
The local Catholic ordinary may grant a dispensation from the canonical form so that the marriage may take place in an Orthodox church witnessed by an Orthodox priest.
This is necessary for the marriage to be recognized as valid by the Orthodox church.
In this case, canonical form is required for liceity, but lack of it does not invalidate the marriage (c. 1127; EGD, no. 10).
The marriage must be witnessed by the Eastern priest.
In rare cases, permission for a Latin Rite priest to witness the marriage must be obtained from the Eastern ordinary through the Tribunal.
The Latin Rite priest must seek the apostolic nuncio's permission, besides the appropriate delegation from the proper Eastern ordinary, if the Latin Rite priest wishes to assist at the marriage of two people, neither of whom is a member of his rite.
In all the above cases, the Latin ordinary has jurisdiction in cases where there is no Eastern bishop with jurisdiction.
Priests should consult the Tribunal when there is doubt.