If the identification of the country of distribution, etc., is unknown, use the abbreviation "S.l." (sine loco, without place) enclosed in brackets and, if necessary, give further explanation in a note.  See 7B11.

245 00 $a [Vaudeville acts] / $c [production company unknown].

257 ## $a [S.l.].

260 ## $a [S.l. : $b s.n., $c 191-]

See also:

4C.  Country of distribution, release, broadcast

4.  Distribution, Release, Broadcast Area