[dhosek]

Indeed, and then there’s the fact that a single codex may contain multiple works, often unrelated (at least to modern eyes—copying of manuscripts was the old school way of adding a book to one’s library, so an abbot in one monastery, learning that another monastery had works X, Y and Z might request they be copied or send a monk to copy them and even though X was a work of theology, Y a poem by Virgil and Z an account of the best way to raise green beans in poor soil, they’d end up together, possibly not even starting a new page when one work ends and the next begins.

And of course, title pages are a later invention so the only way to know what’s in a manuscript is to actually read it.