Compare the term commendaticium used in the title of this canon with the term apostholium/apostolium used i.a. in Canons 1 and 6 of the council of Nîmes AD 394/396 [367], [371]. See also the former canon from the same council: [ 838].
Comparing those two canons, 11 and 12 from Tours, one may notice that Canon 11 talked about the permanent leaving of a particular church and Canon 12 about a temporary absence. In the first case, the cleric required a permission from his bishop (episcopus), but in the second case, a letter of recommendation from the priest (sacerdos) was needed. In the previous canons from the same council, [813] and [815], the term sacerdos was used to describe both bishops and presbyters, and, therefore, it seems that also presbyters could write letters of recommendation for the lower clergy. Indirect proof of this phenomenon can be also found in canon 94 of the Breviary of Ferrandus of Carthage (North Africa, AD 523/546, repeating the earlier norms) [755] and canon 13 of the Second Council of Orléans [1265], forbidding presbyters to issue letters of recommendation.