The MUC disco name is hardcoded to "Public Chatrooms" (MultiUserChatServerImpl:935). We should at least have that string be i18n'ed, probably based on the sessions xml:lang preference. We could also let the value be overridden by setting a Jive property.
We would need to modify the service discovery framework in order to be able to return a service discovery name based on the session xml:lang. Therefore, that feature was postponed to a future version.
For now it is possible to use the system property "muc.service-name" to override the default value based on the current locale.