markup language

n. (Computers) coding system or set of tags used to build or index hypertext documents for the Internet (such as HTML and SGML)

A markup language provides a way to combine a text and extra information about it. The extra information, including structure, layout, or other information, is expressed using markup, which is typically intermingled with the primary text. The best-known markup language in modern use is HTML (HyperText Markup Language), one of the foundations of the World Wide Web. Originally markup was used in the publishing industry in the communication of printed work between authors, editors, and printers.
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Noun
1. a set of symbols and rules for their use when doing a markup of a document
(hypernym) terminology, nomenclature, language
(hyponym) standard generalized markup language, SGML