You must type more letters than <what you’ve already typed> to uniquely identify a command

See Also

This error has the following cause and solution:

• The VSS command line does accept abbreviated versions of its commands.  However, the command line has to be able to distinguish which command you are attempting to use. You've used too few of letters.

  Use more letters in the command to uniquely distinguish it from other commands.  Three letters should be sufficient for uniquely identifying a command.  However, ‘check’ will be interpreted as checkout not checkin.