HTMLVersion
HTMLVersion is a conceptual metadata framework used to indicate the version of HTML that a document adheres to. It is used in development workflows to support validation, compatibility checking, and migration planning by automated tools and content pipelines.
In practice, HTMLVersion is conveyed within the document as metadata. Common approaches include a meta tag
Versioning schemes for HTMLVersion often resemble semantic versioning, using major.minor.patch or a simplified major.minor tag. Major
Adoption and limitations: HTMLVersion has no formal standard in the HTML living standard. Because browsers generally
See also: Doctype, HTML5, Web standards, Validation, Versioning.