How to save a Document or Its Part Using the WBLOCK Command?

Command line: WBLOCK, W, ACADWBLOCKDIALOG
The WBLOCK command is started from the command line and allows saving of an entire document and also part of a drawing using the Write Block dialog: 

The Write Block dialog box complements and extends the capabilities of the Save and Save As commands, allowing the saving of an entire document (Entire drawing parameter) and also part of a drawing (Block and Objects parameters).