Error and warning messages a prefixed as such, but the prefix capitalization varies.

[root@consumer-1 jconnor]# pulp-consumer consumer register --id consumer-1
error:  operation failed: No valid authorization credentials found, please see: pulp-consumer --help
[root@consumer-1 jconnor]# pulp-consumer -u admin -p admin consumer register --id consumer-1
warning: this client is not known to the pulp server; run 'pulp-consumer consumer register' to register it