cupsreject
Reject jobs sent to printers.
TLDR
Reject print jobs to the specified destinations
$ cupsreject [destination1 destination2 ...]
Specify a different server
$ cupsreject -h [server] [destination1 destination2 ...]
Specify a reason string ("Reason Unknown" by default)
$ cupsreject -r [reason] [destination1 destination2 ...]
