Applies to 2018.1 Update and later
All references to a block must be erased before you can purge its block definition.
Purge allows you to remove unused named objects from a drawing at the Command prompt. You can choose to remove nested items all at once or one level of reference at a time. If removing one level of reference at a time, repeat the command until there are no unreferenced, named objects.
Options related to removing unused named objects and some empty geometric objects are displayed.