Why does the Storage Root extensions section talk about what files are allowed in the root itself?

[zimeon]

We have in https://ocfl.io/draft/spec/#storage-root-extensions

An OCFL validator MUST ignore any files in the storage root it does not understand. Additional files MUST not appear in other directories under the storage root.

This isn't anything to do with extensions and:

1. if we want the first MUST is should be in https://ocfl.io/draft/spec/#root-structure
2. the second sentence is duplicative of https://ocfl.io/draft/spec/#E072 and should be removed

[neilsjefferies]

1. What about additional folders in the Storage Root? Is extensions a special case?

[zimeon]

Actually, there seems a conflict around directories in the spec at present. In https://ocfl.io/draft/spec/#root-structure is says:

Sub-directories within an OCFL Storage Root MUST NOT contain files that are not part of an OCFL Object. Empty directories MUST NOT appear within a storage root.

and then in https://ocfl.io/draft/spec/#storage-root-extensions:

The base directory of an OCFL Storage Root MAY contain a directory named extensions for the purposes of extending the functionality of an OCFL Storage Root.

I think the first needs to be rewritten along the lines of:

An OCFL Storage Root MUST NOT contain directories or sub-directories other than as a directory hierarchy used to store OCFL Objects or for storage root extensions. The directory hierarchy used to store OCFL Objects MUST NOT contain files that are not part of an OCFL Object. Empty directories MUST NOT appear under a storage root.