This document was published by the as an Editors Draft. This document is intended to become a W3C Recommendation.

Publication as an Editors Draft does not imply endorsement by the W3C Membership. This is a draft document and may be updated, replaced or obsoleted by other documents at any time. It is inappropriate to cite this document as other than work in progress.

This document is governed by the 1 March 2019 W3C Process Document.