> that's what an old professor told me Well then your prof has no idea what (s)he's talking about I'm afraid. XML is just what the spec says on page 1 sentence

> that's what an old professor told me Well then your prof has no idea what (s)he's talking about I'm afraid. XML is just what the spec says on page 1 sentence 1 [1]: > The Extensible Markup Language (XML) is a subset of SGML that is completely described in this document. Its goal is to enable generic SGML to be served, received, and processed on the Web in the way that is now possible with HTML. Where "generic SGML" refers to the property of XML being always fully tagged and not needing markup declarations, but still able to make use of those for validation and limited forms of entity expansion. Full SGML OTOH uses markup declarations for tag inference/omission (as in HTML), attribute short form canonicalization (also as in HTML), Wiki syntaxes (as in markdown), stylesheets (as in CSS), and other features such as type safe/injection free templating, processing pipelines/document "views" and as general extension mechanism. [1]: https://www.w3.org/TR/REC-xml/ https://www.w3.org/TR/REC-xml/