sentences:  The planned "DR DOS 7.0", internally named "Panther", intended to trump Microsoft's troubled MS-DOS 6.0, was repeatedly delayed, while Novell was working on an optionally loadable Unix-like multi-user security extension (with, if loaded, file commands like ATTRIB, BACKUP, DELPURGE, MOVE, TOUCH, TREE, UNDELETE, XCOPY, XDEL and XDIR supporting an otherwise disabled /U