The procedures followed at assemblies of the Synod of the Bishops are indicated in the
Order of the Synod of Bishops, originally issued in 1969, the latest revision of which was published on 29 September 2006.
Ordinary general assemblies In preparation for each ordinary general assembly, episcopal conferences are asked to suggest up to three themes for discussion. After the secretariat has studied those proposals, the Pope, generally on the basis of the secretariat's recommendation, establishes the topic and agenda of the assembly. Criteria for the choice of the topic are: 1) that it be of universal, not merely regional, interest; 2) that it be pastoral in character with a firm doctrinal base; 3) that it be contemporary and urgent enough to stir up "new energies and movements in the church towards growth"; 4) that it can be addressed within the allotted time. Most participants in the assembly, called
Synodal fathers, are elected by the bishops' conferences: one in the case of a conference with no more than 25 members, two if a conference has up to 50 members, three from a conference with up to 100 members, and four from a larger conference. Other representative participants include heads of
Eastern Catholic Churches, ten members of
religious institutes elected by the Union of Superiors General, and the cardinals who head the Roman Congregations and some other departments of the Roman Curia. Dozens more participate by virtue of synodal functions assigned by the Holy See or as papal appointees, mostly cardinals and other curiate or diocesan prelates.
Fraternal delegates from several Orthodox and Protestant churches (7 each in 2015) have observer status. The secretariat, which includes various other clerical and lay experts, prepares a preliminary outline document (
Lineamenta) which is distributed to all concerned for comment. Based on this feedback, a working document (
instrumentum laboris) is prepared and distributed to all churches. This document is the basis for discussions at the synod. The assembly examines proposals (
propositiones) put forward by its members and passes to the Pope those that receive the assembly's approval. The Pope uses these as the basis for a papal post-synodal
apostolic exhortation. The first general assemblies attempted to draw up their own concluding documents, but found that the time available was insufficient for doing so properly.
Extraordinary general assemblies In view of the greater urgency that justify their convocation, the preparation of extraordinary general assemblies of the Synod of the Bishops is shorter. The participants also are fewer, consisting of the heads of Eastern Catholic Churches, the presidents (only) of episcopal conferences, three members (not ten) of religious institutes and the cardinals who head
dicasteries of the Roman Curia. , there have been three such assemblies, in 1969, 1985, and 2014. The 1985 assembly commemorated the twentieth anniversary of the conclusion of the
Second Vatican Council. Lebanon, and the Netherlands. Another is planned for the Amazon region. ==Chronology==