When IP Multicast Authorization is enforced, this attribute provides the default set of Multicast Authorization Profiles the CMTS enforces for a CM in the case that this CM didn't signal a set of profiles during the registration process. If the Default Multicast Authorization Group Name is zero length string, the DefAction attribute determines whether a join request is authorized when a CM registers without a Multicast Authorization Profile Set or a list of config File Session Rules. If the CMTS supports more than 1 profile name as a default, the CMTS enforces each of the profiles in order until the maximum number of profiles is reached. This attribute indicates one or more Multicast Authorization Profiles.