There are three types of synods: ordinary general assemblies, extraordinary general assemblies and special assemblies.
There have only been two extraordinary synods held since Vatican II. One in 1969 on the theme of cooperation between the Holy See and episcopal conferences, and the second in 1985, held to discuss the 20th anniversary of the conclusion of the second Vatican Council.
The extraordinary synod will be held from October 5-19, 2014, and according to the Vatican it will hear reports from bishops. An ordinary general assembly was already scheduled for 2015 and it will “seek working guidelines in the pastoral care of the person and the family.”
The preparatory document published by the Vatican states that: “Never before has proclaiming the Gospel on the Family in this context been more urgent and necessary.”
It describes the multiple problems that have arisen in recent years, such as the rise in cohabitation, same-sex unions, which also involve the adoption of children, the spread of single parent families, a presumption that the marriage bond can be temporary, an increase in the practice of surrogate motherhood, and a general reformulation of the very concept of the family.
“For example, by simply calling to mind the fact that, as a result of the current situation, many children and young people will never see their parents receive the sacraments, then we understand just how urgent are the challenges to evangelization arising from the current situation, which can be seen in almost every part of the “global village,’” the preparatory document adverted.
The document goes on to explain the biblical foundations and the teaching of the Church on marriage and the family.
Finally, 38 questions are formulated on the diffusion and reception of the teachings of the Church in this respect, on the difficulties of putting them into practice and on their relation with pastoral programs at all levels. Information is also requested on the points that are most attacked and rejected outside ecclesial environments.
Text of preparatory document - http://www.vatican.va/roman_curia/synod/documents/rc_synod_doc_20131105_iii-assemblea-sinodo-vescovi_en.html