Introducing HTML 3.2 には「HTML 3.2 was superseded by HTML 4.0 in December, 1997.」とあり、仕様書には「Superseded 15-March-2018」とある。前者はHTML 4.0を、後者はHTML5を後継仕様として案内している。
"The XML syntax for HTML was formerly referred to as "XHTML", but this specification does not use that term (among other reasons, because no such term is used for the HTML syntaxes of MathML and SVG)." WHATWG. (2023). HTML Living Standard - Last Updated 2 May 2023.
"HTML vs XML syntax ... There are various concrete syntaxes that can be used to transmit resources that use this abstract language, two of which are defined in this specification." WHATWG. (2023). HTML Living Standard - Last Updated 11 January 2023.
"These definitions allow HTML processors ... to present and use documents and applications in a wide variety of contexts that the author might not have considered. ... HTML conveys meaning, rather than presentation" WHATWG. (2023). HTML Living Standard - Last Updated 11 January 2023.
