From the website (accessed 2015-12-14):
The Database of Byzantine Book Epigrams (DBBE) is an ongoing project that makes available textual and contextual data of book epigrams (or: metrical paratexts) from medieval Greek manuscripts (seventh to fifteenth century). We define book epigrams as poems in books and on books: their subject is the very manuscript in which they are found. They record, react to, or motivate the production, the contents and the use of the book. Further explanation of this definition is to be found on the Help page.
Objectives of the database are to: 1) collect textual material that was hitherto dispersed over various publications, chiefly catalogues; 2) clarify the manuscript context of the epigrams; 3) provide ways to search the corpus and detect affinities between epigrams and manuscripts; 4) offer reliable editions that respect the uniqueness of each specific manuscript.