I'm trying to clamp down SSH access to a OS X 10.5 machine. Its a PowerMac used for testing software under the PowerPC.
SSH servers have a "Deny" configuration option that allows us to explicitly deny access based on a user. For a defense-in-depth measure, I want to specifically deny Guest access.
I'm having trouble finding information on what the actual user name is for the Guest Account. The Settings → Users & Groups app does not list it:

Following How can I list all user accounts in the terminal?, the dscacheutil command does not list the account.
And there is no man page on it:
$ man guest
No manual entry for guest
What is the user name associated with the Guest Account?