Last modified: 2012-11-18 10:54:59 UTC
The output of MediaWiki's info action should include the page's internal ID (page.page_id). This is interesting metadata (as the integers are chronologically sequential, largely) and this bit of metadata is currently tucked away in the page source, but not exposed anywhere, making debugging sometimes more tedious than it should be.
https://gerrit.wikimedia.org/r/#/c/17634/ merged