"Compatibility caseless" had been applied to usemap attribute matching. The specification was updated so that case-sensitive matching is applied. https://github.com/whatwg/html/commit/6acdb2122298d2bb7bb839c0a61b4e1f9b0f9bc9 A deprecation warning is printed to the console starting in Chrome 57.
Final published standard: Recommendation, Living Standard, Candidate Recommendation, or similar final form
Status in Chromium
Consensus & Standardization
Search tagsHTML, Image map,
Last updated on 2020-11-09