Hypertext Markup Language (HTML) is the standard markup language for designs displayed in web browsers. This can be helped by technologies such as Cascadin Style Sheets (CSS) and cripting languages like JavaScript.
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Web browsers receive HTML documents from any web server or local storage and render the documents to multimedia web pages. HTML semantically describes the structure of a web page and describes the signals originally included for the document's presence.
Including HTML constructs, images and other objects Such interactive forms can be embedded on the render page. Provides ways to create HTML Structural documents identifying structured semantics for text, such as titles, paragraphs, and lists Links, quotes and other items. HTML elements are tagged by tags using tag brackets. Tags like <img /> /> >
HTML can embed programs written in scripting languages such as JavaScript that affect the behavior and content of web pages. CSS inclusion defines the appearance and format of the content. The World Wide Web Consortium (W3C), a former maintainer of HTML and current maintainer of the CSS standard, has been promoting the use of CSS rather than presentable HTML since 1997-1997.
History
Development
In 1970, physicist Tim Berners-Lee, CERN's contractor, proposed and prototyped Inkier, a system Use and share documents for CRN researchers. In 1989, Berners-Lee offered a memo Internet-based hypertext system. Berners-Lee specified the HTML and wrote the browser and server software In the late 1990s. That year, Berners-Lee and CERN data systems engineer Robert Kiliau collaborated on one. Joint request for funding, but the project has not been formally accepted by CERN. In his personal note Since 1990, he has listed "many of the areas where hypertext is used" and placed an encyclopedia first.
The first publicly available description of HTML was a document called "HTML Tags" It was described by Tim Berners-Lee on the Internet in late 1991, describing the 16 elements that comprise the elementary, HTML relatively simple design. With the exception of hyperlink tags, these were strongly affected SGMLGuide, In-House Standard Generalized Markup Language (SGML) - CERN-based documentation format. Eleven of these elements still exist in HTML4.
HTML is a markup language that web browsers use to interpret and compose text, images, and more. Content on visual or audible web pages. Default attributes for each item in the HTML markup Are defined in the browser and these features can be changed or enhanced by the web properties designer Excessive use of CSS. Many textual materials are available from the 1988 ISO Technical Report TR 9537 Strategies for using SGML, which primarily incorporates features of text formatting languages As used for CNTS by the Runoff Command in the early 1960's (consistent time-sharing) System) operating system: these format commands were derived from the commands used by the typesetter To format documents manually. However the SGML concept of generalized markup is based on elements (Instead of perfect print effects with individual separations (nested annotated ranges with attributes)) Of structure and markup; HTML has been moved towards this with the help of CSS.
Berners-Lee thought HTML was an application of SGML. It was officially defined by such The Internet Engineering Task Force (IETF) published the first proposal in mid-1993. HTML Specification, "Hypertext Markup Language (HTML)" Internet Draft by Berners-Lee and Dan Conley, which includes a SGML document type definition to define grammar. The draft has expired Six months later, however, it was significant for the NCSA Mosaic browser's custom tag to be recognized. Embeds inline images, reflects IETF vision of basing values on successful prototypes Similarly, Dave Raggett's competitive Internet draft, "HTML + (Hypertext Markup Format)", Towards the end of 1993, it was suggested to manipulate tables and fill-out forms, such as already implemented features.
Following the expiration of HTML and HTML + drafts in early 1994, the IETF created an HTML Working Group, which completed "HTML 2.0" in 1995, considering the first HTML specification to be a standard for future implementation.
Further development led by IETF was stalled due to competitive interests. Since 1996, HTML specifications are maintained, including input from commercial software vendors World Wide Web Consortium (W3C). HTML 4.01 was released in late 1999, making it even more flawed 2001. In 2004, the Web Hypertext Application Technology Working Group began developing HTML5. (WHATWG), which became a joint distributor with W3C in 2006 and was completed and standardized on 28 October 2014.
HTML Versions Timeline
HTML 2
November 24, 1995
HTML 2.0 was published as RFC 1866. Supplemental RFCs added capabilities:
* November 25, 1995: RFC 1867
* May 1996: RFC 1942
* August 1996: RFC 1980
* January 1997: RFC 2070
HTML 3
January 14, 1997
HTML 3.2 was released as a W3C proposal. It was the first version developed and standardized exclusively by W3C, since the IETF closed the HTML Working Group on September 12, 1996.
Initially coded as "Wilbur", HTML 3.2 is a complete mathematical formula, reuniting with overlaps between different proprietary extensions, and adopting most of Netscape's visual markup tags. Due to a mutual agreement between the two companies, the flashing material of Netscape and the marquee material of Microsoft were dropped. A markup for similar mathematical formulas in HTML was not standardized until 14 months later in MathML.
December 18, 1997
HTML 4.0 was released as a W3C recommendation. It offers three variations:
* Strict, so that neglected elements are prohibited
* Transitional, where neglected elements are allowed
* Frameset, where in most cases only frame related elements are allowed.
Initially code-named "Cougar", HTML 4.0 adopted many browser-specific component types and features, but at the same time tried to figure out Netscape's visual markup features by identifying them as style sheets. HTML4 is an SGML application that is ISO 8879 - SGML.
April 24, 1998
HTML 4.0 version was republished with minor edits without increasing the number.
December 24, 1999
HTML 4.01 was published as a W3C recommendation. It offers the same three variants as HTML 4.0, and the last bug was published on May 12, 2001.
May 2000
ISO / IEC 15445: 2000 (HTML 4.01 Strike Based "ISO HTML") ISO / IEC International Standards Published ISO / IEC JTC1 / SC34 (ISO / IEC Joint Technical Committee 1, The language of the description and processing of documents).
After HTML 4.01, there were no new versions of HTML for many years because the development of the parallel, XML-based language occupied the HTML W3C's HTML Working Group in the early and mid-2000s.
HTML5 is a markup language used to create and present content on the World Wide Web. This is the fifth and latest version of HTML recommended by the World Wide Web Consortium (W3C). The current specification is known as the HTML Living Standard and is maintained by a consortium of major browser vendors (Apple, Google, Mozilla, and Microsoft), the Web Hypertext Application Technology Working Group (WHATWG).
The form was first released to the public in HTML5, with major updates and “W3C Proposal” status in October 2014. Its goals were to improve the language Support for the latest multimedia and other new features; Both keep the language easy Readable by humans and consistently understood by web browsers such as computers and devices, Parsers etc. without the rigidity of XHTML; And stay backwards compatible with the old software. HTML5 is not just for HTML4, XHTML1 and DOM Level2 are intended for subscribing to HTML.
Includes detailed processed models to encourage more interactive implementation of HTML5; It expands, enhances and rationalizes the markup available for documents, and introduces the markup and application programming interface (API) for complex web applications. For the same reason, HTML5 is also a candidate for cross-platform mobile applications, as it includes features designed with low-powered devices in mind.
Includes many new syntactic features. Incorporate and manage multimedia and graphical locally Content, new <video><audio> and <scanvas> elements were added and supports scalable vectors MathML was added for graphics (SVG) content and mathematical formulas. Enrich the semantics Document contents, new page structure elements such as <sections>, <sections>, <particles>, <titles>, <footers>, <a>> <<> and <figure> have been added. New features were introduced, some elements and features Has been removed, and other <<, <ite> and <menu> have been changed, redefined or standardized. APIs and the Document Object Model (DOM) are now a fundamental part of the HTML 5 specification, And HTML5 gives a better definition of processing for any invalid document.
October 28, 2014
HTML5 was published as a W3C recommendation.
November 1, 2016
HTML 5.1 W3C was published as a recommendation.
December 14, 2017
HTML 5.2 was published as a W3C recommendation.
HTML draft version timeline
October 1991
HTML tags, an unofficial CRN document listing 18 HTML tags, were made public.
June 1992
The first unofficial draft of the HTML DTD, with the next seven amendments (July 15, August 6, August 18, November 17, November 19, November 20, November 22).
November 1992
HTML DTD 1.1 (first with a version number, based on RCS corrections, starting with 1.1 instead of 1.0), an unofficial draft
June 1993
HTML was published by the IETF IIIR Working Group as an Internet Draft (a rough proposal for a standard). It was replaced by a second version one month later.
November 1993
HTML + was published by IETF as an Internet draft and had a competitive offer of Hypertext Markup Language Draft. It ended in July 1994.
November 1994
The first draft of HTML 2.0 (Revision 00) (known as "HTML 2.0" from Amendment 02), published by IETF itself, finally led to the release of RFC 1866 in November 1996.
April 1995
HTML 3.0.0 was proposed to IITF as a standard, but expired five months later (September 26, 1995) without any action. It included many of Rugget's HTML + proposed skills, such as support for tables, text flow around images, and display of complex mathematical formulas.
The W3C began developing its own arena browser as a testing bed for HTML3 and cascading style sheets, However, HTML 3.0 was not successful for various reasons. The draft was considered too large 150 pages and the speed of browser development, as well as the number of interested parties, IETF resources were exceeded. Browser vendors including Microsoft and Netscape At this point, HTML 3 chose to implement several subsets of draft features Introduce their own extensions to it. (See Browser War). This includes extensions for control The stylistic aspects of the document, “as opposed to the belief [of the academic engineering community] There were of course things like text color, background texture, font size, and font face When out of the field of any language their only purpose was to specify how a document would be Organized. Dave Reggett, a W3C Fellow for many years, commented as an example: "To a certain extent, Microsoft builds its business on the web by extending the HTML feature ures."
January 2008
HTML 5 was published by W3C as a working draft.
Although its syntax is similar to SGML, HTML5 has abandoned any attempt to become an SGML application and has clearly defined its own "HTML" serialization in addition to an alternative XML-based XML-5 serialization.
2011 HTML5 – Last Call
On February 14, 2011, W3C extended its HTML Working Group Charter with clear milestones. For HTML5. In May 2011, an invitation to the working group community, “Last Call” improved HTML5 Advanced W3C inside and outside of W3C to ensure technical fluency of specifications A comprehensive test suite to achieve broad intercompatibility for full specification by 2014, Which was the target date for the recommendation. In January 2011, WHATWG changed its name to "HTML5" Live standard of "HTML". Yet W3C is continuing its project to release HTML5.
2012 HTML5 – Candidate Recommendation
In July 2012, WHATWG and W3C decided to separate somewhat. The W3C HTML5 specification will continue to work, centering on a single specific standard, which will be considered a "snapshot" by WHATWG. The WHATWG organization will continue to work with HTML5 as the "Living Standard" with the idea of a live standard it is never complete and is always updated and improved. New features can be added but functionality will not be moved.
In December 2012, W3C nominated HTML5 as a candidate proposal. The progress criteria for the W3C proposal is "two 100% complete and fully interactive implementation".
2014 HTML5 - Recommended Proposals and Recommendations
In September 2014, W3C moved HTML5 to the proposed version.
On October 26, 2014, HTML5 was released as a stable W3C proposal, meaning the specification process is complete.
XHTML Versions
Extensible Hypertext Markup Language (XHTML) is part of the XML markup language family. It mirrors or expands the widely used Hypertext Markup Language (HTML), the language in which web pages are displayed.
HTML, prior to HTML5, was defined as an application of the Standard Generalized Markup Language (SGML), a flexible markup language framework, an application of the XHTML XML, more of the SGML. XHTML documents are well-organized and therefore can be parsed using standard XML parsers as opposed to HTML, which requires a single-line HTML-specific parser.
XHTML 1.0 became the recommendation of the World Wide Web Consortium (W3C) on January 26, 2000. XHTML 1.1 became a W3C recommendation on 31 May 2001.
XHTML is a standalone language that started using XML 1.0 as a reform of HTML 4.01. It is no longer being upgrade as a separate standard.
* XHTML 1.0 was published on 26 January, 2000 as a preface to W3, 2000, and was later revised and republished on 1 August 2002.
* XHTML 1.1 as a W3C recommendation was published on 31 May, 2001. It was published on 10 April , 2001.
* XHTML 2.0 is an executive draft, the work of which was abandoned in 2009 in favor of HTML5 and XHTML5. XHTML 2.0 was inconsistent with XHTML 1.x and, therefore, would have been more accurately identified as an XHTML-inspired new language than an update to XHTML.
* An XHTML syntax, known as "XHTML 5.1", is being defined alongside HTML5 in the HTML5 draft.
Convert HTML publications to WHATWG
On 28 May 2019, W3C announced that WHATWG would be the sole publisher of HTML and DOM standards. W3C and WHATW have been publishing competitive standards since 2012. Although the W3C standard is similar to WHATWG in 2003, the standards have become increasingly distorted due to different design decisions. The WHATWG "Living Standard" has been the de facto web standard for some time.
Markup
<!DOCTYPE html>
<html>
<head>
<title>This is a title</title>
</head>
<body>
<div>
<p>Hello world!</p>
</div>
</body>
</html>
The text between <html> and </html> describes the web page, and the text between <body> and </body> is the content of the visible page. Markup text <title> This is a title </title> defines the title of the browser page and the <div> tag defines a section of the page used for easy styling.
Document type declaration <! DOCTYPE for html> HTML5. If no announcement is included, various browsers will return to "Quirks Mode" for rendering.
Elements
HTML documents refer to a structure of nested HTML elements. These are indicated in the document by HTML tags, enclosed in angle brackets as follows: <p>. [Requires better source]
In general, in general, the range of elements is indicated by a pair of tags: a "start tag" <p> and a "end tag" </p>. The text content of the elements, if any, is placed within these tags.
Tags can turn off more tag markup, including a mix of tags and text at the beginning and end. It refers to more (nested) elements as children of elite elements.
The start tag may also include features within the tag. It refers to other information, such as the identifier for the sections in the document, the identifier used to bind style information to the document presentation, and for some tags such as <emg> embed image, format the image source reference as: <img src = "Example .com / example.jpg "
Some elements such as line break <br> or <br /> do not allow text or subsequent tags in any embedded content. These require only a single blank tag (equivalent to a start tag) and do not use an end tag.
Closing and tag algorithms for many tags, especially the very used paragraph <p>. These rules are complex and are not widely understood by most HTML coders.
The common form of HTML content is: <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 cannot bind any content, For example, online tags or inline <img> tags. Names used in HTML element name tags. Note that the name of the last tag is preceded by a , /, And the last tag in blank elements is not required or allowed. If attributes are not specified, the default value is used in each case.
Element examples
The title of the HTML document: <title ... </head>. The title is included in the header, for example:
<head>
<title>The Title</title>
<link rel="stylesheet" href="stylebyjimbowales.css" /> <!-- Imports Stylesheets -->
</head>
Headings: HTML headings are defined with H1 maximum (or most important) levels and minimum H6 with tags from <h1> to <h6>:
<h1>Heading level 1</h1>
<h2>Heading level 2</h2>
<h3>Heading level 3</h3>
<h4>Heading level 4</h4>
<h5>Heading level 5</h5>
<h6>Heading level 6</h6>
Heading Level 2
Heading Level 3
Heading Level 4
Note that CSS can seriously change the presentation.
Paragraphs:
<p>Paragraph 1</p> <p>Paragraph 2</p>
Line break: The difference between <br> <br> and <p> is that the page breaks a line without changing the semantic structure of the page, while <p> divides the page into paragraphs. Content <br> It is a blank component, although it may have properties, it may not contain any content and may not have end tags.
<p>This <br> is a paragraph <br> with <br> line breaks</p>
This is a link to HTML. The <a> tag is used to create a link. The Href feature retains the URL address of the link.
<a href="https://www.baharidokan.com/">A link to Baharidokan!</a>
Inputs:
There are many ways a user can input / s like:
<input type="text" /> <!-- This is for text input -->
<input type="file" /> <!-- This is for uploading files -->
<input type="checkbox" /> <!-- This is for checkboxes -->
Comments
<!-- This is a comment -->
Comments can help to understand the markup and do not appear on the webpage.
Different types of markup elements are used in HTML:
Structural markup indicates the purpose of the text
For example, <h2> Golf </h2> establishes "Golf" as a second level title. Structured markup does not imply any specific rendering, but most web browsers have a default style for formatting content. Content can be further styled using Cascading Style Sheets (CSS).
The presentational markup indicates the presence of text regardless of the purpose
For example, <b> Boldface </b> indicates that visual output devices should be rendered "boldface" in bold text, However, devices that are unable to do this (such as paired devices that read text aloud) give very little indication of what to do. In both <b> bold </b> and <i> italic </i>, there may be equivalents of other elements. Visual rendering, however, is actually more like a scene, such as <strong> strong text </strong> and <em> emphasized text </em>, respectively. It is easier to see how a covert user agent can explain the next two elements. However, they are not equivalent to their current parts: For example, it would be undesirable for a screen reader to emphasize the name of a book, but such a name would be significant on the screen. Most of the presentation markup elements in favor of using CSS for styling have been deprecated under the HTML 4.0 specification.
Hypertext markup creates parts of a document in links to other documents
An anchor element creates a hyperlink to the document and its href attribute determines the link's target URL. For example, HTML markup <a href="https://www.google.com/"> Wikipedia </a> will render the word "Wikipedia" as a hyperlink. To render an image as a hyperlink, an IMG element is inserted as an element. Like BR, IMG features a blank element but no content or closing tag. <a href="https://example.org "> <img src = "image.gif" alt = "descriptive text" width = "50" height = "50" border = "0"> </a>.
Attributes
The most common feature of an element is the name-value pair, separated by = and written in the beginning tag of an element after the name of the element. The value can be bound to single or double quotes, although values with specific character coordinates may follow HTML (but not XHTML). Leaving prominent values unspoken is considered insecure. In contrast to the name-value pair feature, there are some features that affect The component is simply for the IMG element by their presence at the beginning of the component, like the ismap feature.
There are many common features that can appear in different components:
* The ID feature provides a document-wide unique identifier for any component. It is used to identify the element so that the stylesheets can change its presented features and the scripts can change, animate or delete its content or presentation. Attached to the page URL, it provides a globally unique identifier for the element, usually a subdivision of the page. For example, the ID "Attributes" at https://baharidokan.com/Baharidokan/HTML#Atributes.
* Class properties provide a way to classify similar elements. It can be used For semantic or presentation purposes. For example, an HTML document might be Use the title <class = "notation"> literally to mean this All elements, including the values of this class, are subject to the original text of the document. In presentation, these elements can be presented together Not appearing as a footnote on any page where it appears in the HTML source. Class properties are used semantically in microformats. Multiple class values can be specified; For example, the <class = "notation important"> element contains both the notation and the important class.
* An author can use the style attribute to define features related to the presentation of a particular element. It is a good practice to use the ID or class attributes of an element to select an element from the stylesheet, although sometimes it can be too complicated for general, specific or ad hoc styling.
* The title feature is used to associate subtextual interpretation with an element. This feature is displayed as a tooltip in most browsers.
* The Lang feature identifies the natural language of the content of the component, which may differ from the rest of the document. For example, in an English-language document:
<p>Oh well, <span lang="fr">c'est la vie</span>, as they say in France.</p>
The abbreviation element, Abbar, can be used to display some of these features:
<abbr id="anId" class="jargon" style="color:purple;" title="Hypertext Markup Language">HTML</abbr>
This example is displayed as HTML; In most browsers, the title text "Hypertext Markup Language" will be displayed, briefly pointing to the cursor.
Most elements use language-related features to specify text direction, such as "RTL" for right-to-left text, for example Arabic, Persian or Hebrew.
Character and entity reference
As of version 4.0, HTML defines a set of 252-character entity references and a set of 1,114,050 character references, both allowing individual characters to be written through simple markup instead of literal. A literal character and its markup are considered equivalent equivalents and are presented similarly.
Enable the characters to "escape" in this way, the <and & [characters when & lt; respectively. And & amp; Is written) Interpreted as character data rather than markup. For example, a literal <usually indicates the beginning of a tag and & usually indicates the beginning of a character entity reference or number character reference; Writing it as & amp; & # x26; Or & # 38; And allows the inclusion of any component in the content or compliance of any multiplier. Double-quote characters ("), when not used to quote an attribute value, must also escape as & quot; or & # x22; or & # 34; when it appears in the attribute value. Similarly, the single-quote character ('), when not used to quote the value of an attribute, must escape as & # x27; Or & # 39; (Or as & apos; in HTML5 or XHTML documents) when it appears within the value of the feature. If the authors of the document ignore the need to avoid such characters, some browsers may be very forgiving and try to use the context to guess their purpose. The result is still invalid markup, which makes the document less accessible to other browsers and to other user agents who may try to analyze the document for example for search and indexing purposes.
Escaping also allows for characters that cannot be easily typed, or that are not found in documents Character encoding, elements and attributes to be represented in the content. For example, Intense-pronounced e (é), a character commonly found in Western European and at South American keyboards can be written as an entity reference and eacute in any HTML document; Or as a reference to the number & # xE9; Or & # 233 ;, using available characters Supported on all keyboard and all character encodings. Unicode character encoding Such as UTF-8 compatible with all modern browsers and allows almost direct accessAll the characters in the writing system of the world.
Data Types
HTML defines different types of data for content values, including content data, such as script data and stylesheet data and ID, name, URI, number, unit of length, language, media descriptor, color, character encodings, date and time, and so on. All these data types are character data specia.
Document Type Declaration
HTML documents must start with a document type declaration (unofficially, a "doctype"). Helps to specify doctype rendering mode in browsers - specifically whether to use Quirks mode.
The main purpose of Doctype was to enable parsing and verification of HTML documents by SGML tools based on Document Type Definition (DTD). The DTDDEP refers to DTD as a machine-readable grammar that specifies what is allowed and prohibited content for documents complying with such DTD. Browsers, on the other hand, do not apply HTML as an application of SGML and as a result do not read DTD.
HTML5 does not define a DTD; Therefore, the ductype declaration in HTML5 is simple and short:
<!DOCTYPE html>
An example of an HTML 4 doctype
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "https://www.w3.org/TR/html4/strict.dtd">
This announcement refers to DTDT for the "strict" version of HTML 4.01. SGML-based validators read DTD to parse the document properly and perform validation. Enables a valid desktop standard mode as opposed to Quirks mode in modern browsers.
Additionally, HTML 4.01 provides transitional and frameset DTD as described below. The transitional type is the most included, including the existing tags as well as the old or "depreciation" tags, excluding the Street DTD Notification tag. The Frameset contains all the tags to create a frame on a page, including transitional type tags.
Semantic HTML
Semantic HTML is a way of writing HTML that emphasizes the meaning of encoded information. Its presentation (appearance). HTML has included semantic markup since its inception, but has included it Presentation markup, such as <font>, <i> and <center> tags. There are also semantics Neutral span and DV tags from the late 1990s, when cascading style sheets began To work in most browsers, web authors are encouraged to avoid the use of presentations HTML markup with a view for presentation and content separation.
How Tim Berners-Lee and others gave examples of ways in the 2001 Semantic Web discussion Intelligent software "agents" may one day automatically crawl the web and find, filter and relate Information not previously related, published for the convenience of human users. Such agents are not common Still, some ideas for web 2.0, massup and price comparison websites may come up. The main difference between these web application hybrids and Berners-Lee's semantic agents lies in the fact that the current aggregation and hybridization of information is usually designed in by web developers, who already know the web locations and the API semantics of the specific data they wish to mash, compare and combine.
An important type of web agent that automatically crawls web pages and can read web pages without prior knowledge of what to look for, Web crawler or search engine spider. These software agents rely on the semantic They read and embroider millions of web pages every day and use a variety of techniques and algorithms to help web users search. Without which the usefulness of the World Wide Web will be reduced.
Search engine spiders need to understand the meaning of the pieces of text found in HTML documents and create massups and other hybrids as well as more automated agents so that they can develop.
Presentation markup tags have been reduced to current HTML and XHTML recommendations. Most of the presentation features of previous versions of HTML are no longer allowed because they lead to poor accessibility, higher costs for site maintenance, and larger document sizes.
Good Semantic HTML improves the accessibility of web documents (see also Web Content Accessibility Guidelines). For example, when a screen reader or audio browser can accurately detect the structure of a document, the visually impaired user will not waste time reading it repeatedly or irrelevant information once it is correctly identified.
Delivery
HTML documents can be distributed in the same way as any other computer file. However, most of these are provided over the web server or via HTTP via email.
HTTP
The World Wide Web basically generates HTML documents sent from web servers to web browsers using the Hypertext Transfer Protocol (HTTP). However, HTTP is used to provide images, sound and other content in addition to HTML. How to let the web browser know Other information is transmitted to the document to manage each document it receives. This metadata usually includes mime type (e.g., text / HTML or application / xhtml + xml) and character encoding (see character encoding in HTML).
In modern browsers, the mime time sent with the HTML document can affect how the document is initially interpreted. A document XML sent with XHTML MMIM type is expected to be well organized; The browser may fail to render it due to syntax errors. Same document Sending HTML with MIMIM type may appear to be successful, as some browsers are more flexible with HTML.
The W3C Recommendation states that XHTML 1.0 documents that follow the guidelines set out in Appendix C of the Recommendation may be labeled with mime type. XHTML 1.1 also states that XHTML 1.1 documents should be labeled with mime type.
HTML E-mail
Most graphical email clients allow the use of a subset of HTML (often two-defined) formatting and do not provide semantic markup with plain text. This may include typographic information such as colorful titles, emphasized and quoted text, inline images and diagrams. Many clients like this have a GUI editor and one for composing HTML email messages Rendering engine to display them. Some people criticize the use of HTML in e-mail because of compatibility issues, as it can help disguise phishing attacks due to accessibility issues for blind or visually impaired people, as it can confuse spam filters and because the message size is larger than plain text.
Naming Conventions
The most common file name extension for HTML files. Html. A common abbreviation for this is HTML, the origin of which is due to the limitations imposed by some primary operating systems and file systems, such as DOS and FAT data structures, the limitation of files within three characters.
HTML Application
The HTML application (HTTA; file extension ".hta") is a Microsoft Windows application that uses HTML and dynamic HTML in a browser to provide the application's graphical interface. A regular HTML file is confined to a web browser's security protection model, communicates only to web servers and manipulates only web page content and site cookies. An HTTA is run as a completely trusted application and therefore has more rights like creating / editing / deleting files and Windows registry entries. Since they operate outside of the browser's security model, HTTs cannot be implemented via HTTP, but must be downloaded (like an XE file) and implemented from the local file system.
HTML4 variations
Since its inception, HTML and related protocols have gained relatively rapid acceptance [[by whom?]] However, no clear language values existed early on. Although its creators originally conceived HTML as a semantic language without a description of the presentation, the practical uses push a lot of presentation elements and features into the language, largely driven by different browser vendors. The latest values in the vicinity of HTML reflect the language's efforts to overcome the sometimes chaotic development and create a rational basis for creating both meaningful and well-presented documents. To return HTML to the role of semantic language, to carry the burden of W3C presentation, developed languages like CSS and XSL.
HTML has two axes for different types of variation that are currently described: SGML-based HTML vs. XML-based HTML (known as XHTML), and Strict vs. Transitional (Loose) vs. Frameset of the Other Axis.
SGML-based vs. XML-based HTML
One of the latest HTML specifications differs from the SGML-based variation Specification and XML-based specification. XML-based specifications are commonly called XHTML To distinguish it clearly from the more conventional definitions. But the name of the main ingredient Even XHTML-specific HTML tends to be "HTML". W3C marked XHTML 1.0 as analogy Except in HTML 4.01 where more complex SGML requires a higher amount of work to limit XML because XHTML and HTML are closely related, they are sometimes documented in parallel. In such a situation, Some authors combine the two names as (X) HTML or X (HTML).
Like HTML 5.01, XHTML 1.0 has three sub-specifications: Strict, Transitional, and Frame.s.
With the exception of the various initial declarations for a document, the differences between HTML 3.01 and XHTML 1.0 documents are largely syntactic in each of the respective DTDs. HTML's built-in syntax allows many shortcuts that are not XHTML, such as with elements There are no end tags for opening or closing tags and even blank elements. In contrast, all elements of XHTML need to have an opening tag and a closing tag. XHTML, however, introduced a new shortcut: An XML tag can be opened and closed within the same tag by inserting a slash before the end of a tag: <br/>. Its identity Shorthand, which is not used in SGML declarations for HTML 4.01, may confuse previous software unfamiliar with this new conference. The fix for this is to include a space before closing the tag, such as: <br />.
To understand the subtle differences between HTML and XHTML, consider the conversion of a valid and well-structured XHTML 1.0 document that Appendix C (see below) converts to a valid HTML 4.01 document. This translation requires the following steps:
* The language for an element should be specified with the lang attribute instead of the XHTML XML: lang attribute. XHTML uses XML's built-in language-defined functionality feature.
* Remove the XML namespace (xMLns = URI). There are no benefits for HTML namespaces.
* Change the document type declaration from XHTML 1.0 to HTML 4.01. (See DTD section for further explanation).
* Remove the XML declaration if present. (Usually it is: <? XML version = "1.0" encoding = "utf-8"?>).
* Make sure the document's MIME type text / HTML is set. For both HTML and XHTML it comes from the title of the HTTP content-type sent through the server.
* Change the XML Blank-element Syntax to HTML-style Blank Elements (<br /> <br>).
These are major changes for translating a document from XHTML 1.0 to HTML 4.01. Translating from HTML to XHTML also requires the addition of any omitted opening or closing tags. It is always better to include custom tags in an HTML document than to remember that any tag can be omitted, whether coded in HTML or XHTML.
The W3C proposes several conventions to ensure easy transitions between HTML and XHTML (see HTML Compatibility Guidelines). The following steps can only be applied to XHTML 1.0 documents:
* Include both XML: Lang and Lang attributes in any of the language defined elements.
* Use blank-element syntax for specific elements as HTML empty.
* Add an extra space to the blank-element tags: for example <br> <br /> instead.
* Include explicit intimate tags for elements that are allowed but left blank (for example, not <div> </div>, not <div>).
* Skip the XML announcement.
By carefully following the W3C's Compatibility Guidelines, any user agent should be able to interpret this document equally as HTML or XHTML. For XHTML 1.0 and the way the documents have been adjusted in this way, W3C allows them to serve as HTML. (With a text / HTML mime type), or as XHTML (with an application / XHTML + XML or application / XML mime type). When distributing as XHTML, browsers should use an XML parser, which strictly follows the XML specifications for document content analysis.
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