Errata Item 5: Multiple Category Elements

The Multiple Category Elements errata item on the XACML Wiki (https://wiki.oasis-open.org/xacml/XacmlErrata) states the issue, provides a link to a discussion thread, but is unclear on what specifically needs to change in the XACML specification. Also, the discussion thread indicates that this issue could be resolved in either an errata or implementer's guide.

Requesting a clear indication of what needs to change in the XACML v3.0 specification or should this be added to the implementer's guide?