x-moz-errormessage attribute can be used to have a custom error message when validating a form field. This is a mozilla-only attribute which was rejected in 2010 by w3: https://www.w3.org/Bugs/Public/show_bug.cgi?id=10923
Currently, a similar message can be set using setCustomValidity() method: https://html.spec.whatwg.org/#dom-cva-setcustomvalidity I intent to remove the support for x-moz-errormessage attribute in 66, without any deprecation message because it's unlikely that it would break websites. Let me know if you disagree. Bug: https://bugzilla.mozilla.org/show_bug.cgi?id=1513890 _______________________________________________ dev-platform mailing list dev-platform@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-platform