I'm a bit unclear as to if this is a typo or intended, but in DRS 1.4.0 bulk object access field naming/pluralization seems a bit inconsistent, which I find trips me up a bit when looking to implement the new parts of the spec version:
POST /objects: unresolved_drs_objects vs resolved_drs_object when the contents of resolved_drs_object are multiple
OPTIONS /objects: resolved_drs_object when the contents of resolved_drs_object are multiple, and of type Authorization, not a DRS object