The property of a file indicating access permissions for a process related to the process' user or group identification. A process is in the file ACL class of a file if the process is not in the file owner class and the effective user ID of the process matches the user ID of a user entry in the ACL associated with the file; or if the process is not in the file owner or file group class and the effective group ID or one of the supplementary group IDs of the process matches a group ID of a group entry in the ACL associated with the file.