After a historic introduction the author deals with the manuscript of the Museum of Western Bohemia in Pilsen (5 MA 11). The manuscript entitled 'Inventarium Bibliothecae Archidiaconatus Plsnensis' came into being at the Pilsen archdean Jan Vaclav Emerich's instance. Emerich wrote the book in part (ff . 51r, 54v) himself and in part (ff . 52r-54v) got an unknown scribe (X) to do so. Should an edition of the book be prepared, the complete text by the scribe (X) on ff . 52r-54v will be decisive. This scribe wrote - maybe by mistake.