Since the document seems to have been intended as a complete collection of Ockeghem's music, these movements were probably left out because they were either unavailable either to the copyist or not in a legible condition. Blank opening sections in the codex also imply that at least one other movement, probably a three-voice setting of the Communion in a more sedate style recalling the opening Introit, was originally intended to close the work.
Since the document was intended to be a complete collection of Ockeghem's music, these movements were likely omitted because they were either unavailable or not in good condition. Blank sections at the beginning of the codex suggest that another movement, possibly a three-voice setting of the Communion in a more subdued style reminiscent of the opening Introit, was originally intended to conclude the work.