File attributes are information associated with a file other than the actual data. File attributes may include such things as the owner of the file, the group ownership of the file, an access control list (i.e., a list of users who have access to the file), the file size, and a file serial number. Section 4.1 describes how a system in a network environment could have file systems mounted with different file system structures. Similarly, such a system could have file systems mounted where the files have different file attributes, or the same file attributes but with different semantics associated with the attributes. This should not prevent the files from being accessed transparently.
For example, in Unix and in VMS, there are access permission bits associated with owner access, group access, and access by others (called world access in VMS). However, the algorithm for permitting access based on these permission bits differs between Unix and VMS. In Unix, if the user trying to access a file is the owner, then the system checks only the owner permission bits. If the owner permission bits do not allow access to the file, then access is denied even if the owner is a member of the group and the group access is allowed, or access by others is allowed. In VMS, if the user trying to access a file is the owner and the owner permission bits deny access, then the system will check to see if the user can be granted access on the basis of group or world permissions.