SDC should follow standard URI pattern for RDF dumps, but it does not.
The latest config change in this area was https://gerrit.wikimedia.org/r/c/operations/mediawiki-config/+/609987/9/wmf-config/InitialiseSettings.php
Currently, wikidata's data and entity URI prefixes look like this:
@prefix wd: <http://www.wikidata.org/entity/> . @prefix data: <https://www.wikidata.org/wiki/Special:EntityData/> .
Currently sdc has those prefixes.
@prefix sdc: <https://commons.wikimedia.org/wiki/Special:EntityData/> . @prefix sdcdata: <https://commons.wikimedia.org/wiki/Special:EntityData/> .
With other prefixes build upon data prefix (or, as always, on entity prefix, but here they are identical).
sdc should be similar to wikidata:
@prefix sdc: <https://commons.wikimedia.org/entity/> . @prefix sdcdata: <https://commons.wikimedia.org/wiki/Special:EntityData/> .
The correct prefixes should be:
@prefix sdc: <https://commons.wikimedia.org/entity/> . @prefix sdcdata: <https://commons.wikimedia.org/wiki/Special:EntityData/> . @prefix sdcs: <https://commons.wikimedia.org/entity/statement/> . @prefix sdcref: <https://commons.wikimedia.org/reference/> . @prefix sdcv: <https://commons.wikimedia.org/value/> . @prefix sdct: <https://commons.wikimedia.org/prop/direct/> . @prefix sdctn: <https://commons.wikimedia.org/prop/direct-normalized/> . @prefix sdcp: <https://commons.wikimedia.org/prop/> . @prefix sdcps: <https://commons.wikimedia.org/prop/statement/> . @prefix sdcpsv: <https://commons.wikimedia.org/prop/statement/value/> . @prefix sdcpsn: <https://commons.wikimedia.org/prop/statement/value-normalized/> . @prefix sdcpq: <https://commons.wikimedia.org/prop/qualifier/> . @prefix sdcpqv: <https://commons.wikimedia.org/prop/qualifier/value/> . @prefix sdcpqn: <https://commons.wikimedia.org/prop/qualifier/value-normalized/> . @prefix sdcpr: <https://commons.wikimedia.org/prop/reference/> . @prefix sdcprv: <https://commons.wikimedia.org/prop/reference/value/> . @prefix sdcprn: <https://commons.wikimedia.org/prop/reference/value-normalized/> . @prefix sdcno: <https://commons.wikimedia.org/prop/novalue/> .
NT dumps are also affected.