Block operation Overview
 Mark Box Block                          Alt-B
 Mark Line Block                         Alt-L
 Mark Stream Block                       Alt-X
 Unmark Block                            Alt-U
 Group Delete block                      Alt-G
 Move Block                              Alt-M
 Copy Block                              Alt-C
 Kopy Block                              Alt-K
 Overlay Block                           Alt-O
 Fill box Block                          Alt-F
 Number box Block                        Alt-N
 Print Block                             Alt-P
 Sort box Block                          Alt-S
 Swap Block                              Shift+Alt-S
 Write block to file                     Alt-W
 Block expand tabs                       Alt-E
 Block trim trailing                     Alt-T
 Block upper case                        Alt-<
 Block lower case                        Alt->
 Block strip high bit                    Alt-?
 BlockRot13                              Shift+Alt-<
 BlockFixUUE                             Shift+Alt-<
 BlockEmailReply                         Shift+Alt-?