Problem: Creating texts on Wikisource is a multi-step process. The biggest and most important step is probably just getting the source file onto Commons. Then there are several more steps to get the file into Wikisource (in whichever language). Currently on Wikidata, in the P18 property for image files, the file is recognized automatically while the user types in the Commons filename. There should be a similar effect in reference urls if the file is on Commons and has been added to any Wikisource project. See e.g. these two items, that both reference articles from the same dictionary of biography that is currently on English Wikisource: d:Q38103276 and d:Q43194364. Currently only the first one has an associated article from the Wikisource file at d:Q38103904.
Who would benefit: Anyone contributing to Wikidata and adding references from Commons or via Commons, Wikisource.
Proposed solution: Make the Commons link obligatory when adding Wikisource articles to Wikidata so that they can be "recognized" on the basis of the .djvu filename. This will dissolve the language silos that keep this information unobtainable to reference-contributors.
Proposer: Jane023 (talk) 10:38, 20 November 2017 (UTC)
@Jane023: maybe I miss your point but there is something strange with your links to Wikidata, could you check them? (d:Q38103276 and d:Q43194364 are not biography entries but the actual people Q5 and I linked Mary H. Graves - the woman, to Mary H. Graves - the dictionary entry)
That is by design: those items reference the same djvu file used on Wikisource. Jane023 (talk) 11:38, 30 November 2017 (UTC)
Comment Making links obligatory on Wikidata is not a task for WMF's Community Tech team. Can we solve it by adding a constraint to a property? --Jarekt (talk) 12:43, 1 December 2017 (UTC)
I didn't ask for anything to be obligatory. I would like the links to be recognized for what they are (like sitelinks are recognized when you type them in). Jane023 (talk) 12:29, 2 December 2017 (UTC)