The current definition of certifierCredential states:

Identifies a credential or badge that establishes the authority of the party identified in the certifiedBy property to certify content accessible

This is too general a statement, as more than one certification can be listed, so more than one certifier can be listed, too.

We didn't use the refines attribute to tie the two together because it was expected to be deprecated in 3.1, but we should correct that now.

The definition should say "in the associated certifiedBy property" and the refines attribute should be added to the example.

/cc @GeorgeKerscher @avneeshsingh @clapierre