realm {<number> {<sectors>}}
    (No '?' pattern allowed.) Set the realm (0 - 5) to the indicated
    rectangle of sectors. You should set up some realms, so that you aren't
    in danger of mistyping a sector range. If no 'sectors' specification is
    given, then the current one is display. If no arguments are given, then
    all realms are displayed.
Doc: intro, sectors, economics
Help: nation, map, syntax