Sermones Bernardi (Tomus I). A leaf useda s a paste-down, containing an otherwise unknown motet; the rear board contains a 'mirror image' offset of the pages. The front board has an offset of a page removed from this book and now f. 2v of MS B 1328, a motet by Machaut.
See also Lerch's reconstruction of these and other fragments as 'F-CA(n)'.