From Using batch parameters [microsoft.com]:
Cmd.exe provides the batch parameter expansion variables %0 through %9. When you use batch parameters in a batch file, %0 is replaced by the batch file name, and %1 through %9 are replaced by the corresponding arguments that you type at the command line
These batch parameter modifiers variable arguments are immensely useful.
That . . . → Read More: Using batch parameter modifiers to get specific portions or file info from a full filename
