Nicene and Post-Nicene Fathers, Ser. II, Vol. XIV:
The Canons of the Councils of Ancyra, Gangra, Neocæsarea, Antioch and Laodicea, which Canons were Accepted and Received by the Ecumenical Synods.: Canon VII

Canon VII.

No stranger shall be received without letters pacifical.

Notes.

Ancient Epitome of Canon VII.

A traveller having no letter pacific with him is not to be received.

Compare the Apostolic Canon number XXXIII.

For a discussion of the Letters styled pacifici, see notes on next canon.

This canon is found in the Corpus Juris Canonici, Gratian’s Decretum, Pars I., Dist. lxxi., c. ix. in Isidore’s version.  The Roman Correctors note that Dionysius must have had a different reading from the Greek we know.