Some copies of
the Gutenberg Bible have very extensive manuscript notes. They help
to understand how these copies were used. Some of them state that
they were used for reading out in a refectory, for monks during their
The British Library's copies do not give us such clear information, but in some passages there are marks to assist with the pronunciation of the Latin, indicating that the copy of the Bible was in part intended to be used for reading aloud. There are also a few corrections to the text.
The best discussion of marks of use in the Gutenberg Bible is Gerhardt Powitz, Die Frankfurter Gutenberg-Bibel: Ein Beitrag zum Buchwesen des 15. Jahrhunderts (Frankfurt am Main: Klostermann, 1990). ISBN 3465022319.