A document type declaration , or DOCTYPE , is an instruction that associates a particular XML or SGML document (for example, a web page ) with a document type definition (DTD) (for example, the formal definition of a particular version of HTML 2.0 - 4.0 ). In the serialized form of the document, it manifests as a short string of markup that conforms to a particular syntax.
79-559: The HTML layout engines in modern web browsers perform DOCTYPE "sniffing" or "switching", wherein the DOCTYPE in a document served as text/html determines a layout mode, such as " quirks mode " or "standards mode". The text/html serialization of HTML5 , which is not SGML-based, uses the DOCTYPE only for mode selection. Since web browsers are implemented with special-purpose HTML parsers, rather than general-purpose DTD-based parsers, they do not use DTDs and never access them even if
158-501: A DOCTYPE declaration which is very short, due to its lack of references to a DTD in the form of a URL or FPI. All it contains is the tag name of the root element of the document, HTML . In the words of the specification draft itself: <!DOCTYPE html> , case-insensitively. With the exception of the lack of a URI or the FPI string (the FPI string is treated case sensitively by validators), this format (a case-insensitive match of
237-455: A Document type declaration (informally, a "doctype"). In browsers, the doctype helps to define the rendering mode—particularly whether to use quirks mode . The original purpose of the doctype was to enable the parsing and validation of HTML documents by SGML tools based on the Document type definition (DTD). The DTD to which the DOCTYPE refers contains a machine-readable grammar specifying
316-466: A public text , i.e. one shared between multiple computer systems (regardless of whether it is an available public text available to the general public, or an unavailable public text shared only within an organisation). If the PUBLIC keyword is used, it is followed by the public identifier enclosed in double or single ASCII quotation marks. The public identifier does not point to a storage location, but
395-528: A "Proposed Recommendation" rather than a draft. An implementation of MathML 2 landed in WebKit around this same time, with a Chromium implementation following a couple of years later, although that implementation was removed from Chromium after less than a year. The Second Edition of MathML 3.0 was published as a W3C Recommendation on 10 April 2014. The specification was approved as an ISO/IEC international standard 40314:2015 on 23 June 2015. Also in 2015,
474-426: A "system identifier" that is likewise enclosed in quotation marks. Although the interpretation of system identifiers in general SGML is entirely system-dependent (and might be a filename, database key, offset, or something else), XML requires that they be URIs . For example, the FPI for XHTML 1.1 is "-//W3C//DTD XHTML 1.1//EN" and, there are 3 possible system identifiers available for XHTML 1.1 depending on
553-482: A DOCTYPE declaration is surrounded by literal square brackets ( [] ), and called an internal subset . It can be used to add/edit entities or add/edit PUBLIC keyword behaviors. It is possible, but uncommon, to include the entire DTD in-line in the document, within the internal subset, rather than referencing it from an external file. Conversely, the internal subset is sometimes forbidden within simple SGML profiles, notably those for basic HTML parsers that don't implement
632-516: A URL is provided. The DOCTYPE is retained in HTML5 as a "mostly useless, but required" header only to trigger "standards mode" in common browsers. The general syntax for a document type declaration is: or The opening <!DOCTYPE syntax is followed by separating syntax (such as spaces, or (except in XML) comments opened and closed by a doubled ASCII hyphen ), followed by a document type name (i.e.
711-423: A World Wide Web page may read as follows: This document type declaration for XHTML includes by reference a DTD, whose public identifier is -//W3C//DTD XHTML 1.0 Transitional//EN and whose system identifier is http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd . An entity resolver may use either identifier for locating the referenced external entity. No internal subset has been indicated in this example or
790-407: A contractor at CERN , proposed and prototyped ENQUIRE , a system for CERN researchers to use and share documents. In 1989, Berners-Lee wrote a memo proposing an Internet -based hypertext system. Berners-Lee specified HTML and wrote the browser and server software in late 1990. That year, Berners-Lee and CERN data systems engineer Robert Cailliau collaborated on a joint request for funding, but
869-433: A full SGML parser. If both an internal DTD subset and an external identifier are included in a DOCTYPE declaration, the internal subset is processed first, and the external DTD subset is treated as if it were transcluded at the end of the internal subset. Since earlier definitions take precedence over later definitions in a DTD, this allows the internal subset to override definitions in the external subset. The first line of
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#1732772402322948-510: A hundred different elements for different functions and operators. For example, <apply><sin/><ci> x </ci></apply> represents sin ( x ) {\displaystyle \sin(x)} and <apply><plus/><ci> x </ci><cn> 5 </cn></apply> represents x + 5 {\displaystyle x+5} . The elements representing operators and functions are empty elements, because their operands are
1027-665: A namespace immediately after the Namespace Recommendation was completed, and for XML use, the elements should be in the namespace with namespace URL http://www.w3.org/1998/Math/MathML . When MathML is used in HTML (as opposed to XML) this namespace is automatically inferred by the HTML parser and need not be specified in the document. Version 3 of the MathML specification was released as a W3C recommendation on 20 October 2010. A recommendation of A MathML for CSS Profile
1106-400: A pair is the start tag , and the second is the end tag (they are also called opening tags and closing tags ). Another important component is the HTML document type declaration , which triggers standards mode rendering. The following is an example of the classic "Hello, World!" program : The text between < html > and </ html > describes the web page, and
1185-425: A start tag) and do not use an end tag. Many tags, particularly the closing end tag for the very commonly used paragraph element < p > , are optional. An HTML browser or other agent can infer the closure for the end of an element from the context and the structural rules defined by the HTML standard. These rules are complex and not widely understood by most HTML authors. The general form of an HTML element
1264-670: A summation index. The new <share> element allows structure sharing. The development of MathML 3.0 went through a number of stages. In June 2006, the W3C rechartered the MathML Working Group to produce a MathML 3 Recommendation until February 2008, and in November 2008 extended the charter to April 2010. A sixth Working Draft of the MathML 3 revision was published in June 2009. On 10 August 2010 version 3 graduated to become
1343-596: A user can give input/s like: Comments: Comments can help in the understanding of the markup and do not display in the webpage. There are several types of markup elements used in HTML: Most of the attributes of an element are name–value pairs , separated by = and written within the start tag of an element after the element's name. The value may be enclosed in single or double quotes, although values consisting of certain characters can be left unquoted in HTML (but not XHTML). Leaving attribute values unquoted
1422-579: Is also supported in HTML5 files. There is no need to specify namespaces as there was in XHTML . Another standard called OpenMath that has been more specifically designed (largely by the same people who devised Content MathML) for storing formulae semantically can be used to complement MathML. OpenMath data can be embedded in MathML using the <annotation-xml encoding= "OpenMath" > element. OpenMath content dictionaries can be used to define
1501-495: Is built up out of tokens that are combined using higher-level elements, which control their layout. Finer details of presentation are affected by close to 50 attributes. Token elements generally only contain characters (not other elements). They include: Note, however, that these token elements may be used as extension points, allowing markup in host languages. MathML in HTML5 allows most inline HTML markup in mtext, and <mtext><b> non </b> zero </mtext>
1580-415: Is conforming, with the HTML markup being used within the MathML to mark up the embedded text (making the first word bold in this example). These are combined using layout elements, that generally contain only elements. They include: As usual in HTML and XML, many entities are available for specifying special symbols by name, such as π and → . An interesting feature of MathML
1659-464: Is considered unsafe. In contrast with name-value pair attributes, there are some attributes that affect the element simply by their presence in the start tag of the element, like the ismap attribute for the img element. There are several common attributes that may appear in many elements : The abbreviation element, abbr , can be used to demonstrate some of these attributes: This example displays as HTML ; in most browsers, pointing
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#17327724023221738-456: Is for HTML5. If a declaration is not included, various browsers will revert to " quirks mode " for rendering. HTML documents imply a structure of nested HTML elements . These are indicated in the document by HTML tags , enclosed in angle brackets thus: < p > . In the simple, general case, the extent of an element is indicated by a pair of tags: a "start tag" < p > and "end tag" </ p > . The text content of
1817-602: Is merely a list of HTML entity names. Strict DTD does not allow presentational markup with the argument that Cascading Style Sheets should be used for that instead. This is how the Strict DTD looks: Transitional DTD allows some older PUBLIC and attributes that have been deprecated: If frames are used, the Frameset DTD must be used instead, like this: XHTML 's DTDs are also Strict, Transitional and Frameset. XHTML Strict DTD. No deprecated tags are supported and
1896-411: Is often assisted by technologies such as Cascading Style Sheets (CSS) and scripting languages such as JavaScript, a programming language. Web browsers receive HTML documents from a web server or from local storage and render the documents into multimedia web pages. HTML describes the structure of a web page semantically and originally included cues for its appearance. HTML elements are
1975-494: Is rather a unique fixed string intended to be looked up in a table (such as an SGML catalog ); however, in some (but not all) SGML profiles, the public identifier must be constructed using a particular syntax called Formal Public Identifier (FPI), which specifies the owner as well as whether it is available to the general public. The public identifier (if present) or SYSTEM keyword (otherwise) may (and, in XML, must) be followed by
2054-485: Is that entities also exist to express normally-invisible operators, such as ⁢ (or the shorthand ⁢ ) for implicit multiplication. They are: The full specification of MathML entities is closely coordinated with the corresponding specifications for use with HTML and XML in general. Thus, the expression a x 2 + b x + c {\displaystyle ax^{2}+bx+c} requires two layout elements: one to create
2133-469: Is the only information which it is mandatory to give in a DOCTYPE declaration. The DOCTYPE declaration can optionally contain an external identifier , following the root element name (and separating syntax such as spaces), but before any internal subset. This begins with either the keyword SYSTEM or the keyword PUBLIC , specifying whether the DTD is specified using a public identifier identifying it as
2212-401: Is therefore: < tag attribute1 = "value1" attribute2 = "value2" > ''content'' </ tag > . Some HTML elements are defined as empty elements and take the form < tag attribute1 = "value1" attribute2 = "value2" > . Empty elements may enclose no content, for instance, the < br /> tag or
2291-557: Is to natively integrate mathematical formulae into World Wide Web pages and other documents. It is part of HTML5 and standardised by ISO /IEC since 2015. Following some experiments in the Arena browser based on proposals for mathematical markup in HTML, MathML 1 was released as a W3C recommendation in April 1998 as the first XML language to be recommended by the W3C . Version 1.01 of
2370-439: The <annotation> element, which can be used to embed a semantic annotation in non-XML format, for example to store the formula in the format used by an equation editor such as StarMath or the markup using LaTeX syntax. The encoding field is usually a MIME type , although most of the equation encodings don't have such a registration; freeform text may be used in such cases. Although less compact than other formats,
2449-589: The Internet Engineering Task Force (IETF) with the mid-1993 publication of the first proposal for an HTML specification, the "Hypertext Markup Language (HTML)" Internet Draft by Berners-Lee and Dan Connolly , which included an SGML Document type definition to define the syntax. The draft expired after six months, but was notable for its acknowledgment of the NCSA Mosaic browser's custom tag for embedding in-line images, reflecting
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2528-548: The SIGIR conference proposed that the semantic knowledge base Wikidata could be used as an OpenMath Content Dictionary to link semantic elements of a mathematical formula to unique and language-independent Wikidata items. The well-known quadratic formula could be represented in Presentation MathML as an expression tree made up from layout elements like <mfrac> or <msqrt> : This example uses
2607-434: The de facto web standard for some time. HTML markup consists of several key components, including those called tags (and their attributes ), character-based data types , character references and entity references . HTML tags most commonly come in pairs like < h1 > and </ h1 > , although some represent empty elements and so are unpaired, for example < img > . The first tag in such
2686-410: The presentation but also the meaning of formula components (the latter part of MathML is known as "Content MathML"). Because the meaning of the equation is preserved separate from the presentation, how the content is communicated can be left up to the user. For example, web pages with MathML embedded in them can be viewed as normal web pages with many browsers, but visually impaired users can also have
2765-460: The "bare" HTML5 DTD, older XHTML/HTML DTDs, DTDs of common embedded XML-based formats like MathML and SVG as well as "compound" documents that combine those formats. Both W3C HTML5 and its corresponding WHATWG version recommend browsers to only accept XHTML DTDs of certain FPIs and to prefer using internal logic over fetching external DTD files. It further specifies an "internal DTD" for XHTML which
2844-441: The DTD in order to properly parse the document and to perform validation. In modern browsers, a valid doctype activates standards mode as opposed to quirks mode . MathML Mathematical Markup Language ( MathML ) is a mathematical markup language , an application of XML for describing mathematical notations and capturing both its structure and content, and is one of a number of mathematical markup languages . Its aim
2923-456: The IETF's philosophy of basing standards on successful prototypes. Similarly, Dave Raggett 's competing Internet Draft, "HTML+ (Hypertext Markup Format)", from late 1993, suggested standardizing already-implemented features like tables and fill-out forms. After the HTML and HTML+ drafts expired in early 1994, the IETF created an HTML Working Group. In 1995, this working group completed "HTML 2.0",
3002-530: The MathML Association was founded to support the adoption of the MathML standard. At that time, according to a member of the MathJax team, none of the major browser makers paid any of their developers for any MathML-rendering work; whatever support existed was overwhelmingly the result of unpaid volunteer time/work. In August 2021, a new specification called MathML Core was published, described as
3081-465: The XML declaration, DOCTYPE declaration, and document element. The document body then contains MathML expressions which appear in < math > elements as needed in the document. Often, MathML will be embedded in more general documents, such as HTML , DocBook , or other XML -based formats. Presentation MathML focuses on the display of an equation, and has about 30 elements. The elements' names all begin with m . A Presentation MathML expression
3160-417: The XML structuring of MathML makes its content widely usable and accessible, allows near-instant display in applications such as web browsers , and facilitates an interpretation of its meaning in mathematical software products. MathML is not intended to be written or edited directly by humans. MathML, being XML, can be embedded inside other XML files such as XHTML files using XML namespaces. Inline MathML
3239-498: The XML syntax for HTML and is no longer being developed as a separate standard. On 28 May 2019, the W3C announced that WHATWG would be the sole publisher of the HTML and DOM standards. The W3C and WHATWG had been publishing competing standards since 2012. While the W3C standard was identical to the WHATWG in 2007 the standards have since progressively diverged due to different design decisions. The WHATWG "Living Standard" had been
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3318-473: The attribute value itself. If document authors overlook the need to escape such characters, some browsers can be very forgiving and try to use context to guess their intent. The result is still invalid markup, which makes the document less accessible to other browsers and to other user agents that may try to parse the document for search and indexing purposes for example. Escaping also allows for characters that are not easily typed, or that are not available in
3397-574: The browser, and these characteristics can be altered or enhanced by the web page designer's additional use of CSS . Many of the text elements are mentioned in the 1988 ISO technical report TR 9537 Techniques for using SGML , which describes the features of early text formatting languages such as that used by the RUNOFF command developed in the early 1960s for the CTSS (Compatible Time-Sharing System) operating system. These formatting commands were derived from
3476-486: The building blocks of HTML pages. With HTML constructs, images and other objects such as interactive forms may be embedded into the rendered page. HTML provides a means to create structured documents by denoting structural semantics for text such as headings, paragraphs, lists, links , quotes, and other items. HTML elements are delineated by tags , written using angle brackets . Tags such as < img > and < input > directly introduce content into
3555-433: The characters < and & (when written as < and & , respectively) to be interpreted as character data, rather than markup. For example, a literal < normally indicates the start of a tag, and & normally indicates the start of a character entity reference or numeric character reference; writing it as & or & or & allows & to be included in
3634-441: The characters of the world's writing systems. HTML defines several data types for element content, such as script data and stylesheet data, and a plethora of types for attribute values, including IDs, names, URIs , numbers, units of length, languages, media descriptors, colors, character encodings, dates and times, and so on. All of these data types are specializations of character data. HTML documents are required to start with
3713-516: The code must be written correctly according to XML Specification. XHTML Transitional DTD is like the XHTML Strict DTD, but deprecated tags are allowed. XHTML Frameset DTD is the only XHTML DTD that supports Frameset. The DTD is below. XHTML 1.1 is the most current finalized revision of XHTML, introducing support for XHTML Modularization . XHTML 1.1 has the stringency of XHTML 1.0 Strict. XHTML Basic 1.0 XHTML Basic 1.1 HTML5 uses
3792-451: The commands used by typesetters to manually format documents. However, the SGML concept of generalized markup is based on elements (nested annotated ranges with attributes) rather than merely print effects, with separate structure and markup. HTML has been progressively moved in this direction with CSS. Berners-Lee considered HTML to be an application of SGML. It was formally defined as such by
3871-487: The content of an element or in the value of an attribute. The double-quote character ( " ), when not used to quote an attribute value, must also be escaped as " or " or " when it appears within the attribute value itself. Equivalently, the single-quote character ( ' ), when not used to quote an attribute value, must also be escaped as ' or ' (or as ' in HTML5 or XHTML documents ) when it appears within
3950-664: The cursor at the abbreviation should display the title text "Hypertext Markup Language." Most elements take the language-related attribute dir to specify text direction, such as with "rtl" for right-to-left text in, for example, Arabic , Persian or Hebrew . As of version 4.0, HTML defines a set of 252 character entity references and a set of 1,114,050 numeric character references , both of which allow individual characters to be written via simple markup, rather than literally. A literal character and its markup counterpart are considered equivalent and are rendered identically. The ability to " escape " characters in this way allows for
4029-589: The document's character encoding , to be represented within the element and attribute content. For example, the acute-accented e ( é ), a character typically found only on Western European and South American keyboards, can be written in any HTML document as the entity reference é or as the numeric references é or é , using characters that are available on all keyboards and are supported in all character encodings. Unicode character encodings such as UTF-8 are compatible with all modern browsers and allow direct access to almost all
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#17327724023224108-445: The element, if any, is placed between these tags. Tags may also enclose further tag markup between the start and end, including a mixture of tags and text. This indicates further (nested) elements, as children of the parent element. The start tag may also include the element's attributes within the tag. These indicate other information, such as identifiers for sections within the document, identifiers used to bind style information to
4187-695: The expression rather than its layout. Central to Content MathML is the <apply> element that represents function application. The function being applied is the first child element under <apply> , and its operands or parameters are the remaining child elements. Content MathML uses only a few attributes. Tokens such as identifiers and numbers are individually marked up, much as for Presentation MathML, but with elements such as <ci> and <cn> . Rather than being merely another type of token, operators are represented by specific elements, whose mathematical semantics are known to MathML: <times> , <power> , etc. There are over
4266-517: The first HTML specification intended to be treated as a standard against which future implementations should be based. Further development under the auspices of the IETF was stalled by competing interests. Since 1996, the HTML specifications have been maintained, with input from commercial software vendors, by the World Wide Web Consortium (W3C). In 2000, HTML became an international standard ( ISO / IEC 15445:2000). HTML 4.01
4345-635: The format was released in July 1999 and version 2.0 appeared in February 2001. Implementations of the specification appeared in Amaya 1.1 , Mozilla 1.0 and Opera 9.5 . In October 2003, the second edition of MathML Version 2.0 was published as the final release by the W3C Math Working Group . MathML was originally designed before the finalization of XML namespaces . However, it was assigned
4424-412: The head, for example: HTML headings are defined with the < h1 > to < h6 > tags with H1 being the highest (or most important) level and H6 the least: The effects are: CSS can substantially change the rendering. Paragraphs: < br /> . The difference between < br /> and < p > is that < br /> breaks a line without altering
4503-425: The hyperlink tag, these were strongly influenced by SGMLguid , an in-house Standard Generalized Markup Language (SGML)-based documentation format at CERN. Eleven of these elements still exist in HTML 4. HTML is a markup language that web browsers use to interpret and compose text, images, and other material into visible or audible web pages. Default characteristics for every item of HTML markup are defined in
4582-402: The inline < img > tag. The name of an HTML element is the name used in the tags. The end tag's name is preceded by a slash character, / , and that in empty elements the end tag is neither required nor allowed. If attributes are not mentioned, default values are used in each case. Header of the HTML document: < head > ... </ head > . The title is included in
4661-465: The look and layout of content. The World Wide Web Consortium (W3C), former maintainer of the HTML and current maintainer of the CSS standards, has encouraged the use of CSS over explicit presentational HTML since 1997. A form of HTML, known as HTML5 , is used to display video and audio, primarily using the < canvas > element, together with JavaScript. In 1980, physicist Tim Berners-Lee ,
4740-587: The many operator and function elements amount to Scheme functions. With this trivial literal transformation, plus un-tagging the individual tokens, the example above becomes: This reflects the long-known close relationship between XML element structures, and LISP or Scheme S-expressions . According to the OM Society, OpenMath Content Dictionaries can be employed as collections of symbols and identifiers with declarations of their semantics – names, descriptions and rules. A 2018 paper presented at
4819-716: The meaning of <csymbol> elements. The following would define P 1 ( x ) to be the first Legendre polynomial : The OMDoc format has been created for markup of larger mathematical structures than formulae, from statements like definitions, theorems, proofs, and examples, to complete theories and even entire text books. Formulae in OMDoc documents can either be written in Content MathML or in OpenMath; for presentation, they are converted to Presentation MathML. The ISO / IEC standard Office Open XML (OOXML) defines
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#17327724023224898-466: The name of the root element that the DTD applies to trees descending from). In XML, the root element that represents the document is the first element in the document. For example, in XHTML, the root element is <html>, being the first element opened (after the doctype declaration) and last closed. Since the syntax for the external identifier and internal subset are both optional, the document type name
4977-467: The needs. One of them is the URL reference "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd" . It means that the XML parser must locate the DTD in a system specific fashion, in this case, by means of a URL reference of the DTD enclosed in double quote marks. In XHTML documents, the doctype declaration must always explicitly specify a system identifier. In SGML-based documents like HTML, on
5056-422: The next ones. The root element is declared to be html and, therefore, it is the first tag to be opened after the end of the doctype declaration in this example and the next ones, too. The HTML tag is not part of the doctype declaration but has been included in the examples for orientation purposes. Some common DTDs have been put into lists. W3C has produced a list of DTDs commonly used in the web, which contains
5135-408: The other elements under the containing <apply> . The expression a x 2 + b x + c {\displaystyle ax^{2}+bx+c} could be represented as Content MathML is nearly isomorphic to expressions in a functional language such as Scheme and other dialects of Lisp . <apply> ... </apply> amounts to Scheme's ( ... ) , and
5214-429: The other hand, the appropriate system identifier may automatically be inferred from the given public identifier. This association might e.g. be performed by means of a catalog file resolving the FPI to a system identifier. The SYSTEM keyword can (except in XML) also be used without a system identifier following, indicating that a DTD exists but should be inferred from the document type name. The last, optional, part of
5293-410: The overall horizontal row and one for the superscripted exponent. However, the individual tokens also have to be identified as identifiers ( <mi> ), operators ( <mo> ), or numbers ( <mn> ). Adding the token markup, the full form ends up as A complete document that consists of just the MathML example above, is shown here: Content MathML focuses on the semantics, or meaning, of
5372-413: The page. Other tags such as < p > and </ p > surround and provide information about document text and may include sub-element tags. Browsers do not display the HTML tags but use them to interpret the content of the page. HTML can embed programs written in a scripting language such as JavaScript , which affects the behavior and content of web pages. The inclusion of CSS defines
5451-434: The permitted and prohibited content for a document conforming to such a DTD. Browsers, on the other hand, do not implement HTML as an application of SGML and as consequence do not read the DTD. HTML5 does not define a DTD; therefore, in HTML5 the doctype declaration is simpler and shorter: An example of an HTML 4 doctype This declaration references the DTD for the "strict" version of HTML 4.01. SGML-based validators read
5530-412: The presentation of the document, and for some tags such as the < img > used to embed images, the reference to the image resource in the format like this: < img src = "example.com/example.jpg" > Some elements, such as the line break < br /> do not permit any embedded content, either text or further tags. These require only a single empty tag (akin to
5609-491: The project was not formally adopted by CERN. In his personal notes of 1990, Berners-Lee listed "some of the many areas in which hypertext is used"; an encyclopedia is the first entry. The first publicly available description of HTML was a document called "HTML Tags", first mentioned on the Internet by Tim Berners-Lee in late 1991. It describes 18 elements comprising the initial, relatively simple design of HTML. Except for
5688-541: The root element referenced inside the HTML5 DOCTYPE . The DOCTYPE is optional in XHTML5 and may simply be omitted. However, if the markup is to be processed as both XML and HTML , a DOCTYPE should be used. HTML Hypertext Markup Language ( HTML ) is the standard markup language for documents designed to be displayed in a web browser . It defines the content and structure of web content . It
5767-622: The same MathML read to them through the use of screen readers (e.g. using the VoiceOver in Safari ). JAWS from version 16 onward supports MathML voicing as well as braille output. The quality of rendering of MathML in a browser depends on the installed fonts. The STIX Fonts project have released a comprehensive set of mathematical fonts under an open license. The Cambria Math font supplied with Microsoft Windows had slightly more limited support. A valid MathML document typically consists of
5846-423: The semantic structure of the page, whereas < p > sections the page into paragraphs . The element < br /> is an empty element in that, although it may have attributes, it can take no content and it may not have an end tag. This is a link in HTML. To create a link the < a > tag is used. The href attribute holds the URL address of the link. There are many possible ways
5925-579: The string !DOCTYPE HTML ) is the same as found in the syntax of the SGML based HTML 4.01 DOCTYPE . Both in HTML4 and in HTML5, the formal syntax is defined in upper case letters, even if both lower case and mixes of lower case upper case are also treated as valid. In XHTML5 the DOCTYPE must be a case-sensitive match of the string " <!DOCTYPE html> ". This is because in XHTML syntax all HTML element names are required to be in lower case, including
6004-517: The text between < body > and </ body > is the visible page content. The markup text < title > This is a title </ title > defines the browser page title shown on browser tabs and window titles and the tag < div > defines a division of the page used for easy styling. Between < head > and </ head > , a < meta > element can be used to define webpage metadata. The Document Type Declaration <!DOCTYPE html>
6083-407: The “core subset of Mathematical Markup Language, or MathML, that is suitable for browser implementation.” MathML Core set itself apart from MathML 3.0 by including detailed rendering rules and integration with CSS , automated browser support testing resources, and focusing on a fundamental subset of MathML. An implementation was added to Chromium at the beginning of 2023. MathML deals not only with
6162-457: Was later released on 7 June 2011; this is a subset of MathML suitable for CSS formatting. Another subset, Strict Content MathML , provides a subset of content MathML with a uniform structure and is designed to be compatible with OpenMath . Other content elements are defined in terms of a transformation to the strict subset. New content elements include <bind> which associates bound variables ( <bvar> ) to expressions, for example
6241-515: Was published in late 1999, with further errata published through 2001. In 2004, development began on HTML5 in the Web Hypertext Application Technology Working Group (WHATWG), which became a joint deliverable with the W3C in 2008, and was completed and standardized on 28 October 2014. XHTML is a separate language that began as a reformulation of HTML 4.01 using XML 1.0. It is now referred to as
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