The filter tool edits the parse trees, selectively deleting nodes based on a filter specification that is supplied by command line switches.
The filter specification consists of a global policy, either keep or delete, and per construct keep and delete directives. The per construct directives are applied first, any unmatch constructs are handle by the default policy. Note not all constructs are allowed in the filter specification, those that are omited are keep by default. The follow switches are used to specify the filter specification:
See the Man Page for the complete list of which constructs may be specified in the filter specification.