Q. 1. What is the "Canonical Form of Matrimony?"
A. 1. The "Canonical Form of Matrimony" is a ruling that took place on November 11, 1563 AD on matrimonial law at the Council of Trent. In simple English, the Catholic Church wrote the Canon Laws that are associated with the Sacrament of Marriage.
As a result of the Tametsi Decree, it was stipulated that any marriage that took place outside the presence of a parish priest or his representative and two witnesses would be null. Places where priests were not available were excepted, and it was not binding where the laws of Trent were not promulgated. It was extened almost universally in a modified form by the "Ne Temer Decree" of Pope Pius X in 1908 AD.
"It (was) declared, however, that the Church has always disapproved of marriages contracted secretly, or without the consent of parents. This same chapter of the Tridentine Council prescribes the promulgation of the banns of marriage, which is a repetition of the Fourth Lateran Council, the form expressing consent to be used and the inscribing of the marriage in the parochial register. It declares also that any priest, secular or regular, other than the pastor, assisting at a marriage or giving the solemn nuptial blessing without proper delegation is suspended at once and remains under suspension till rightly absolved by the ordinary of the parish priest of the contracting parties. This censure, however, is no longer incurred, though punishment may be meted out to those who offend in this matter. Finally, "Tametsi" recommends that those about to marry approach the Sacraments of Penance and the Eucharist, and that local customs and rites connected with marriage be observed."
[Catholic Encyclopedia; http://www.newadvent.org/cathen/14441b.htm]