From memory or formulary: how were medieval documentary formulae reproduced?

This paper reviews the state of the art concerning how documentary formulae were reproduced in early medieval private charters written in Latin. It assesses the theoretical considerations and empirical evidence supporting one or the other of the two main hypotheses: i) that charter scribes copied the formulae from models or ii) that they had memorized the formulae and reproduced them from memory each time they wrote a new charter. While proposing that the memorization hypothesis is more robust, I also recognise intermediate positions.