What "Rebuilt" means

The time when an article is rebuilt is the most recent time when the makefile used to create the HTML and PDF versions of articles caused Pandoc to process the article source file.

This time is not necessarily when the article text was last changed, since the rebuild might have been triggered by alterations to metadata in the header or auxiliary files, or by a regression test that the makefile still successfully builds the HTML and PDF versions of all my articles.