Dimissorial letters (in Latin, litterae dimissoriae) are testimonial letters given by a bishop or by a competent religious superior to his subjects in order that they may be ordained by another bishop. Such letters testify that the subject has all the qualities demanded by canon law for the reception of the order in question, and request the bishop to whom they are addressed to ordain him.[1]
The plural term is often used of a single document because of the influence of the Latin term, since in that language litterae, which literally means letters (of the alphabet) can also mean a letter (in the sense of message).
Before the entry into force of the Code of Canon Law in 1917, the term had a wider sense (see the article in the Catholic Encyclopedia of that period). The conditions for issuing dimissorial letters were also different and were more complicated.