How should third-party accessibility issues be included in Accessibility Conformance Reports (ACRs) or other documentation?

There are a few options to present this information. Some clients list it in their Voluntary Product Accessibility Template (VPAT) under a "Does Not Support" or "Partially Supports" area. Here, you can explicitly state the templates that include third-party content and include the failures they contain. You can also include it in your public accessibility statement. Here, you can present your VPAT and explain the third-party content issues you are having while detailing how they affect your VPAT.