Currently, the documentation only provides one example of "Disallowed tag ancestor" error:

Currently, the only example is a template tag, which may not be nested under another template tag.

However, it seems that the svg tag is cannot be nested under amp-nested-menu either.
Could it be added?

If not, we should document that "The tag 'svg' may not appear as a descendant of tag 'amp-nested-menu'."