Sometimes referred to as De arte grammatica, the Doctrinale by Alexander of Villedieu (XII secolo), a Norman, is a work consisting of more than 2600 hexameters that, in groups, enunciate various grammar rules of the Latin language. The text’s objective evidently was to facilitate learning through the pursued mnemonic technique: this task was got, if we consider that this was one of the most used texts for Latin teaching in the grammar schools all over Europe until the sixteenth century. This manuscript of the Guarneriana Library, which does contain the Doctrinale, as well as the Notabilia by Giovanni of Soncino (Guarner. 129), is part of that group of codices Guarnerio d'Artegna either owned before starting his merely humanistic librarian collection or, more likely, he purchased upon the death of his friend, perhaps his teacher, Giovanni of Spilimbergo. This is a dated codex whose copying work was completed in 1423 by a scribe that, while providing the colophon with quite precise chronological details, reveals his name, as well, in a sort of charade: «Explicit liber magistri Alexandri de Villa Dei. Deo dicamus gratias, amen. Manus scriptoris laudetur omnibus horis. Nomen scriptoris si tu cognoscere queris, ‘Mi’ tibi sit primo, medio ‘cha’, ‘el’ sit in ymo. Completum extitit dictum opus per supradictum scriptorem anno nativitatis Domini millesimo CCCC XXIII°, die XXa mensis aprelis, hora vigesima» (f. 54v).