MS-DOS Secret Commands?

Below is a listing of MS-DOS commands that are not listed in any available help manual or in the commands syntax or are commonly unknown commands. Many of these commands that are known can be very useful when using MS-DOS, while some of the other commands are unknown or appear to do nothing.
Caution: Use these commands cautiously, some of the commands can erase data and some without warning.

ATTRIB ,	The command is short for ATTRIB -a -h -r – s *.* (removes all attributes of a file).
BACKUP /HP	Unknown
DIR ,	This lists all files including hidden files, does not work in Windows 95, 98, NT, and 2000.
DIR …	Lists all directories that do not have extensions. In Windows 95 and Windows 98 will list the contents of the directories previous to the directory currently in.
DOSKEY /APPEDIT	Utilize doskey functions in MS-DOS command utilities such as edlin and debug.
DOSKEY /COMMAND	Unknown
DOSKEY /PERMANENT	Unknown
DOSKEY /SCRSIZE	Unknown
DOSKEY /XHISTORY	Unknown
FDISK /MBR	Recreates the Master Boot Record See CH000175 for additional information.
FDISK /PRI	See FDISK Page for additional information.
FDISK /EXT	See FDISK Page for additional information.
FDISK /LOG	See FDISK Page for additional information.
FDISK /Q	Prevents fdisk from booting the system automatically after exiting fdisk.
FDISK /STATUS	Shows you the current status of your hard drives.
FORMAT /AUTOTEST	Formats the hard drive without any prompting.
FORMAT /BACKUP	Like /AUTOTEST but it will ask you for a volume label.
FORMAT /Z:n	Command used with FDISK supporting FAT32, used to specify the cluster size in bytes where n is multiplied by 512.
MEM /A or /ALL	Adds a line into the MEM command tells the available space in HMA.
RESTORE /Y	Unknown
RESTORE /Z	Unknown
SET DIRCMD=0	Make all directories hidden however still accessible, to get them back SET DIRCMD=
SHARE /NC	Unknown
TRUENAME	When placed before a file, displays the whole directory that exists.
VER /R	Tells you the Revision and if DOS is in HMA.