[template] Groups that maintain living standards should have charter language that supports those standards' use as normative references

[jyasskin]

To use a document as a normative reference, the W3C (and other standards organizations) look for indications that the referenced parts of the document are sufficiently stable. The WHATWG makes an explicit promise to only update their living standards in coordination with implementations of those standards, but I don't see any equivalent promise from W3C groups about how they'll accept breaking changes in their specs.

It seems plausible to put this in group charters, either in the Decision Policy ("This group must not decide to accept a change to <some identification of its living standards> unless <paste some criteria from the WHATWG policy>") or in the description under Normative Specifications for each one that's expected to be a living standard.