File psl-1983/3-1/doc/nmode/nm-mark.key from the latest check-in
.silent_index {C-X} idx 10-1 .silent_index {C-@} idx 10-1 .silent_index {C-Space} idx 10-1 .silent_index {C-X} idx 10-1 .silent_index {M-@} idx 10-2 .silent_index {C-M-@} idx 10-2 .silent_index {C->} idx 10-2 .silent_index {C-<} idx 10-2 .silent_index {M-H} idx 10-2 .silent_index {C-M-H} idx 10-2 .silent_index {C-X} idx 10-2 .silent_index {C-U} idx 10-2 .silent_index {C-U} idx 10-2