The sidebar link to Wikimedia Commons on various Wikipedias currently uses P373. It would be better to use the interwiki sitelinks to Commons instead. The logic in this case would be:
- If there is a sitelink to Commons in the attached Wikidata item, use that (optional: unless it is to a gallery page)
- If there is a P910 value, follow that to the category item and use the sitelink to Commons from there
- If there is a P1754 value, follow that to the category item and use the sitelink to Commons from there
- Otherwise, display nothing.
This follows the logic of the "_getCommonslink" function of https://commons.wikimedia.org/wiki/Module:WikidataIB - which is used to display the links in https://en.wikipedia.org/wiki/Template:Commons_category .
This is one of the blockers for the eventual deletion of P373 from Wikidata - see the ongoing discussion at https://www.wikidata.org/wiki/Wikidata:Properties_for_deletion#Property:P373