Back in 2012, the WHATWG set out to document the differences between the ECMAScript 5.1 specification and the compatibility and interoperability requirements for ECMAScript implementations in web browsers.
- figuring out implementation differences for various non-standard features;
- filing browser bugs to get implementations to converge;
- and finally writing specification text for the common or most sensible behavior, hoping it would one day be upstreamed to ECMAScript.
That day has come.
The infamous “string HTML methods”:
Similarly, ECMAScript now has spec text for
ECMAScript Annex B, which specifies things like
-->). As of ECMAScript 2015, Annex B fully defines this syntax.