Canon 27 is one of the six canons (24-29) attributed to the First Council of Arles which are transmitted by only two codices (Parisiensis Lat. 12448 and Bodl. 893). Compare with canon 7 of the Council Thelense (North Africa, AD 418), see [275].
Bishops (here described as fratres – "brothers") should not accept into their clergy clerics who abandoned their own church. Apparently, doing so had in the past resulted in some troubling quarrels between bishops.