Bishop_III has acquired a free link in a LINK_OK room.  He sees an unlinked
  exit called "404" in Hallway(#700RL).  He can make a home by creating
  a room and linking the free exit to it:
@dig The Bishop's Room
> Room The Bishop's Room dug with number #738.
@link 404=#738
@desc 404=This door leads to Bishop_III's room.
@osucc 404=enters Bishop_III's room, number 404.
@odrop 404=enters from the Hallway.

  Then he enters the new room and creates the backlink, very important:
go 404
> The Bishop's Room(#738R)
@open out;exit;leave;w;west=#700
@desc out=This exit leads out to the Hallway.
@osucc out=leaves the room.
@odrop out=steps out of Bishop_III's room.
@desc here=This is a spartan chamber with a minicomputer running AutoCAD.

  He sets his home here by doing:
@link me=here