• The opening delimiter <! used in SGML and HTML to begin markup declarations such as doctype declarations, comments, and processing instructions. This two-character sequence signals to the parser that a markup declaration follows rather than regular element content.

1. Related terms: Markup Declaration Close, Markup language, Doctype, Declaration
2. Previous term: Markup Declaration Close
3. Next term: Markup language
4. Random term: ALA (webglossary.info/random 🎲)