What is option "-P" to smbclient?

[Kent West]

In trying to print to a printer hanging off a Windows box, I find that 
the smbprint script has this line:

        echo "print -"
        cat
) | smbclient "\\\\$server\\$service" -U $password -N -P >> $logfile
I have been unable to find any documentation that explains what the 
option "-P" is for (am I just blind?). Anyone know?

Thanks!

Kent