In BSD, a set of attributes governing who can read, write, and execute resources in the file system. The output of the ls -l command represents permissions as a nine-position code segmented into three binary three-character subcodes; the first subcode gives the permissions for the owner of the file, the second for the group that the file belongs to, and the last for everyone else. The left-most position is reserved for a special character that says if this is a regular file (-), a directory (d), a symbolic link (l), or a special pseudo file device. The execute bit has a different semantic for directories, meaning they are searchable. See also ACL, authorization, UID.