When restoring the description in this section (see CDA-20952, based on 2022 Errata CDA-1682 / CDA-1623) - a key sentence exists here:

When using this section in a Care Plan document, do not include an Assessment or an Assessment and Plan Section.

The Assessment and Plan section now actually enforces a similar restriction globally. This could be done for this section likewise. If the restriction is ONLY to be on the Care Plan document, then the invariant should be written in the Care Plan Document template. If, however, the intent is to never allow this section in a document with either the Assessment Section or the Assessment & Plan Section, then the sentence should be updated, and the invariant placed in this section (like the current invariant exists in the Assessment & Plan Section).