### `++umph`

    ++  umph                                                ::  change filter
              $|  $?  %a                                    ::  no filter
                      %b                                    ::  jamfile
                      %c                                    ::  LF text
                  ==                                        ::
              $%  [%d p=@ud]                                ::  blocklist
              ==                                            ::

See `%clay` doc