[Info-vax] BACKUP to the null device

[Phillip Helbig---undress to reply]

Whu does BACKUP to NL:FOO.BAR give the error %BACKUP-F-INVDEVTYP but to 
NL:FOO.BAR/SAVE_SET work?  If the error is correct in the first case, 
why doesn't it apply in the second, since in both cases the target is a 
file with the same device, directory, name, type and version?