I received this response:
root@barbershop:~# /usr/lib/mailman/bin/withlist caljente Loading list caljente (unlocked) The variable `m' is the caljente MailList instance
m.preferred_language
'nl'
m.description
'Lijst voor Caljent\xe9-leden'
Not sure what encoding that is. I've changed it to "Caljente" for now, which should be a reasonable workaround.