When using Nrzviewer from the command line, there's a documented switch called /zenrights, which uses rights instead of password authentication.

I can't get this to work.

I get the message "Ticket not provided for rights authentication."

The log looks like this:
Started and Winsock (v 2) initialised
Connected to port 5950
RFB server supports protocol version 3.7
Connected to RFB server, using protocol version 3.7
Authentication scheme: Novell authentication
Sent console version information...
Novell Encryption: Cant read certificate file
Novell Encryption: Verify mode:0
Novell Encryption: Finished initializing all the parameters
Initialized Novell TLS Encryption...
Novell Encryption: Performing SSL handshake...
Verification of server certificate returned: 20.
Initialized SSL Encryption...
Ticket not provided for Rights Authentication.
Deinitialized Novell Encryption for the session...
VNC viewer closing down

Any ideas?

By the way, remoting from the ZCC works, and so does password-based authentication from the command line.