EWTN has the following:
Motu ProprioA document issued Motu Proprio is from the Pope on his own initiative, and not in response to a request or at the initiative of others. Its legal determinations carry the full force of papal authority, though it does not derogate from existing laws unless specifically stated. It can be any category of document.
In teaching, it includes solemn Magisterial acts of the Pope; in governance, erecting dioceses, changing their status, rules for a papal election and the like.
A circular or general letter expressing the mind of the Pope, generally on matters of faith and morals. It may be a letter to the entire Church or an epistle to a particular Church or people (e.g. Mit brennenden sorge, Pius XI's encyclical to the German people condemning racism).
Letters of less solemn authority than an encyclical, they may be written on a doctrinal matter (e.g. Pope John Paul II's Letter On the Beginning of the Third Millennium). They may also announce a papal act such as declaring a person Venerable (heroic virtue) or declaring a church a Basilica.
A category of document similar to an Apostolic Letter, which Pope John Paul II uses to communicate to the Church the conclusions he has reached after consideration of the recommendations of a Synod of Bishops. He has also used it in other circumstances, such as to exhort religious to a deeper evangelical life.
A joint statement of the Holy Father and another religious leader concerning a common understanding of some teaching.
The homilies of the Pope on the Scripture readings at Mass.
General Audience - The opportunity to hear and/or greet the Holy Father is called an audience. On Wednesdays, when he is in Rome, he will have a General Audience, either in the Paul VI audience hall or in St. Peter's Square. The discourses at these Audiences are typically used to develop a theme over a long period. An entry ticket, which is free, is required.
Private Audience - The Pope also holds private audiences with individuals and groups, at which he will also speak on a pertinent subject, such as on medical issues to groups of doctors, world affairs to diplomats and Church teaching and procedures to curial officials.
In settings outside Mass (at which his address is called a homily) or outside the usual audience setting, the Pope may give a discourse to groups of people, upon arriving or departing a place, before or after Mass, at a rosary or in some circumstance not a homily or an audience.
Written or spoken messages, often conveying a personal greeting, to individuals or groups. Usually briefer than a letter or an allocution.