Add CREF about ambiguous behaviour of additionalProperties

Fixes json-schema-org#1172
Must see new issue relating to the behaviour of annotation collection for resolving in the next draft.

Author: Relequestual

jsonschema-core.xml

@@ -2480,6 +2480,28 @@
                             checking the names in "properties" and the patterns in
                             "patternProperties" against the instance property set.
                             Implementations that do not support annotation collection MUST do so.
+                            <cref>
+                                In defining this option, it seems there is the potential for
+                                ambiguity in the output format. The ambiguity does not affect validation results,
+                                but it does affect the resulting output format.
+                                The ambiguity allows for multiple valid output results depending on whether annotations
+                                are used or a solution that "produces the same effect" as draft-07. It is understood
+                                that annotations from failing schemas are dropped. See
+                                https://github.com/json-schema-org/community/discussions/57 for details.
+                                We discussed the possible solutions at length (https://github.com/json-schema-org/json-schema-spec/issues/1172).
+                                We concluded that we need to re-evaluate the annotation collection system
+                                and its use for validation purposes, but we also agreed not to do so for this release.
+                                This confusion stemmed from the understanding of "evaluated" and the impact on
+                                annotation collection.
+                                It was proposed that we could read a different interpretation (https://github.com/json-schema-org/json-schema-spec/issues/1172#issuecomment-1049686478)
+                                however the previous interpretation is still valid.
+                                The only consensus we could reach for this release was to note all this
+                                in a CREF, which you're now reading, and acknowledge that both results
+                                as described in https://github.com/json-schema-org/community/discussions/57.
+                                If you encounter the same issue regarding ambiguity of the output format,
+                                please do reach out to us, either via emails as per editors of this specification,
+                                or other official JSON Schema channels like our Slack or Twitter.
+                            </cref>
                         </t>
                     </section>