Property:Query source
From Wicri Île-de-France (en)
Change propagation updates are pending (28 jobs estimated) and it is recommended to wait with modifications to a property until the process has been finalized to prevent intermediary interruptions or contradictory specifications.
"Query source" is a predefined property provided by Semantic MediaWiki that identifies alternative (e.g. remote, federated) query sources. This property is pre-deployed (also known as special property) and comes with additional administrative privileges but can be used just like any other user-defined property.