A writer’s ability (or inability) to append his/her signature to a document is instrumental in understanding his/her literacy degree; in a quantitatively broader context, it may significantly contribute to assessing the degree of dissemination of writing skills in a given geographical area and/or across a specific chronological span. Besides this merely numerical aspect the study of signings makes it possible to identify how many people and which social categories were involved in the relevant documentation; further to this an analysis of the writing skills to be identified with reference to any such occurrence and their formal characte- ristics helps to define the education and learning processes in which the identified signatories were involved as well as the different graphical models in use within a given society so as to reconstruct the evolution of writing and its reference models. Based on such remarks we thought that this investigation methodology could also be applied to the available early medieval Arretine sources with a view to identify forms and functions of writing in Arezzo between the 9th and the 11th century, its degree of diffusion as well as the related teaching patterns as our attention focused on that particular social category known as the «laymen».