Internal forum is a term used in moral

Morality

Morality is the differentiation among intentions, decisions, and actions between those that are good and bad . A moral code is a system of morality and a moral is any one practice or teaching within a moral code...

 theology referring to the private realm of one's personal conscience

Conscience

Conscience is an aptitude, faculty, intuition or judgment of the intellect that distinguishes right from wrong. Moral judgement may derive from values or norms...

 or an act of judgement applying the universal truth to a particular situation, such as the Sacrament of Penance. The term is frequently used in association with dealing with decisions that cannot be adequately handled in the public external forum regulated by canon law

Canon law

Canon law is the body of laws & regulations made or adopted by ecclesiastical authority, for the government of the Christian organization and its members. It is the internal ecclesiastical law governing the Catholic Church , the Eastern and Oriental Orthodox churches, and the Anglican Communion of...

, such as in cases involving the reception of the Eucharist

Eucharist

The Eucharist , also called Holy Communion, the Sacrament of the Altar, the Blessed Sacrament, the Lord's Supper, and other names, is a Christian sacrament or ordinance...

 by those who have civilly divorced and remarried without an annulment

Annulment

Annulment is a legal procedure for declaring a marriage null and void. Unlike divorce, it is usually retroactive, meaning that an annulled marriage is considered to be invalid from the beginning almost as if it had never taken place...

. Although the supremacy of conscience is acknowledged in the Catholic Church, such a conscience must be properly formed.

In the Roman Curia

Roman Curia

The Roman Curia is the administrative apparatus of the Holy See and the central governing body of the entire Catholic Church, together with the Pope...

, the Apostolic Penitentiary

Apostolic Penitentiary

The Apostolic Penitentiary, formerly called the Supreme Tribunal of the Apostolic Penitentiary, is one of the three tribunals of the Roman Curia. The Apostolic Penitentiary is chiefly a tribunal of mercy, responsible for issues relating to the forgiveness of sins in the Catholic Church.The...

has jurisdiction for matters in the internal forum.