Margins and flyleaves in medieval manuscripts had a literary life of their own. Often, they were filled with ever-growing layers of various minuscule texts: e.g., pen trials and scribal notes, recipes and prayers, glosses and poems. The latter are a particularly interesting case: Of course, not every verse was added for a deeper reason. Occasionally, authors (or literary-loving scribes) simply used any free spot they could find. But in many cases, such poetic additions interact with the original content of the manuscript. In the case of an Exlibris or dedication, this happens in an obvious way because they hint at the social and institutional context, at donors, owners, and users. Other examples are more complex though, and poetry serves a hermeneutic frame, instructing the readers about the religious or epistemological meaning of the book they hold in their hands. The aim of the paper is to introduce some examples of poetic frames and explore their forms and functions.