The overlay lint accepted any D-number, so another issue's ruling such
as "D5 (#245)" could mark a concept override. A marker now has to be a
D-number with no other issue cited; the vocabulary rule that cited #245
reads "#245 decision 5". TESTING.md now states that the lint covers
workspace.css only, lists the unmarked overrides still in images.css,
and says PRs C and D run the lint over each page sheet they keep.
Vito Sansevero