The comment in https://ocfl.io/1.1/spec/#object-structure:
The OCFL Object Root MUST NOT contain files or directories other than those specified in the following sections.
is perhaps not as clear as it might be with regard to which the "following sections" are. We could make that explicit:
The OCFL Object Root MUST NOT contain files or directories other than those specified in the following sections (3.2 through 3.9).