1 - /ALL

    Deletes all symbols from the specified table. If you do not
    specify either the /LOCAL or the /GLOBAL qualifier, all symbols
    defined at the current command level are deleted. The /ALL
    qualifier is incompatible with the symbol-name parameter.

2 - /GLOBAL

    Deletes the symbol from the global symbol table of the current
    process.

3 - /LOCAL

       /LOCAL (default)

    Deletes the symbol from the local symbol table of the current
    process.

4 - /LOG

       /LOG
       /NOLOG (default)

    Controls whether an informational message listing each symbol
    being deleted is displayed.