The Latin manuscript 4650 of the Bavarian State Library is a collection of templates for charters and letters (so-called formulae) most probably written in Salzburg in the late ninth or early tenth century. Some of these formulae have only been transmitted in that manuscript, but most have been transmitted else-where as collections and were probably composed a few generations earlier. It is therefore obvious that this manuscript is a patchwork (or the copy of such a heterogeneous collection), but the heterogeneity of the sources is not apparent at first sight. Only a close analysis of the sequence of the formulae, the use of red ink, and small textual changes permits an appreciation of the technique of medieval scribes when adapting previous models for the creation of new collections more suitable to their own needs.