Editing Markup language (section)

==Types of markup language==
There are three main general categories of electronic markup, articulated in Coombs, Renear, and [[Steven Derose|DeRose]] (1987),<ref>{{cite journal |date=November 1987 |title=Markup systems and the future of scholarly text processing |journal=[[Communications of the ACM]] |volume=30 |issue=11 |pages=933–947 |doi=10.1145/32206.32209 |url=http://xml.coverpages.org/coombs.html |first1=James H. |last1=Coombs |first2=Allen H. |last2=Renear |first3=Steven J. |last3=DeRose |citeseerx=10.1.1.515.5618 |s2cid=59941802 |access-date=2005-04-19 |archive-date=2019-05-12 |archive-url=https://web.archive.org/web/20190512040939/http://xml.coverpages.org/coombs.html |url-status=live }}</ref> and [[Tim Bray|Bray]] (2003).<ref>{{cite web |last=Bray |first=Tim |author-link=Tim Bray |url=https://www.tbray.org/ongoing/When/200x/2003/04/09/SemanticMarkup#p-1 |title=On Semantics and Markup, Taxonomy of Markup |website=www.tbray.org |date=9 April 2003 |access-date=2021-08-16 |archive-date=2021-02-27 |archive-url=https://web.archive.org/web/20210227074013/https://www.tbray.org/ongoing/When/200x/2003/04/09/SemanticMarkup#p-1 |url-status=live }}</ref>

=== Presentational markup ===
:The kind of markup used by traditional [[Word processor (electronic device)|word-processing]] systems: [[Binary code|binary codes]] embedded within document text that produce the [[WYSIWYG]] ("'''what you see is what you get'''") effect. Such markup is usually hidden from human users, even authors and editors. Properly speaking, such systems use procedural and/or descriptive markup underneath but convert it to "present" to the user as geometric arrangements of type.{{Citation needed|date=February 2024}}

=== Procedural markup ===
:Markup is embedded in text which provides [[Opcode|instructions]] for [[Programming language|programs]] to process the text. Well-known examples include [[troff]], [[TeX]], and [[Markdown]]. It is assumed that software processes the text sequentially from beginning to end, following the instructions as encountered. Such text is often edited with the markup visible and directly manipulated by the author. Popular procedural markup systems usually include [[Process (computing)|programming constructs]], especially [[Macro (computer science)|macros]], allowing complex sets of instructions to be invoked by a simple name (and perhaps a few parameters). This is much faster, less error-prone, and more maintenance-friendly than re-stating the same or similar instructions in many places.

=== Descriptive markup ===
: Markup is specifically used to label parts of the document for what they are, rather than how they should be processed. Well-known systems that provide many such labels include [[LaTeX]], [[HTML]], and [[XML]]. The objective is to [[Separation of content and presentation|decouple the structure]] of the document from any particular treatment or rendition of it. Such markup is often described as "[[Semantic HTML|semantic]]". An example of a descriptive markup would be HTML's <code>&lt;cite></code> tag, which is used to label a citation. Descriptive markup — sometimes called ''logical markup'' or ''conceptual markup'' — encourages authors to write in a way that describes the material conceptually, rather than visually.<ref>Michael Downes.[https://www.ams.org/notices/200211/comm-downes.pdf "TEX and LATEX 2e"] {{Webarchive|url=https://web.archive.org/web/20210524182136/http://www.ams.org/notices/200211/comm-downes.pdf |date=2021-05-24 }}</ref>

There is a considerable blurring of the lines between the types of markup. In modern word-processing systems, presentational markup is often saved in descriptive-markup-oriented systems such as [[XML]], and then processed procedurally by [[Implementation|implementations]]. The programming in procedural-markup systems, such as [[TeX]], may be used to create higher-level markup systems that are more descriptive in nature, such as [[LaTeX]].

In recent years, several markup languages have been developed with ease of use as a key goal, and without input from standards organizations, aimed at allowing authors to create formatted text via [[Web browser|web browsers]], for example in [[wiki]]s and in [[Internet forum|web forums]]. These are sometimes called [[lightweight markup language]]s. [[Markdown]], [[BBCode]], and the [[Wikitext|markup language used by Wikipedia]] are examples of such languages.