related-article-type should have one of the following values: "addendum", "commentary-article", "companion", "series", "retracted-article", "corrected-article", "concerning-article", "translated-article", "republished-article", "response-to", or "publisher-note"
Articles with article-type "correction" must include a related-article[@related-article-type="corrected-article"].
Articles with article-type "retraction" must include a related-article[@related-article-type="retracted-article"].
Articles with article-type "expression-of-concern" must include a related-article[@related-article-type="concerning-article"].
Articles with related-article-type "concerning-article" must have article-type "expression-of-concern"
Articles with related-article-type "retracted-article" must have article-type "retraction"
Articles with related-article-type "corrected-article" must have article-type "correction"
related-article must have attributes ext-link-type="doi" and xlink:href containing a DOI, or have attributes ext-link-type="uri" and xlink:href containing a URI that starts with http or https and is not a DOI URL.