Globale linker
Book 1
- Chapter 1
- Chapter 2
- Chapter 3
- Chapter 4
- Chapter 5
- Chapter 6
- Chapter 7
- Chapter 8
- Chapter 9
- Chapter 10
- Chapter 11
- Chapter 12
- Chapter 13
- Chapter 14
- Chapter 15
- Chapter 16/17
- Chapter 18/19
- Chapter 20
- Chapter 21
- Chapter 22/23
Book 2
Ch.11 HTML Standards and Compliance
HTML is cross-platform accessible. That is the result of the World Wide Web Concortium's (W3C) maintenance and development of standards.
HTML = Hypertext Markup Language, invented by Tim Berners-Lee of the Massachusetts Institute of Technology, as a means of distributing nonlinear text called hypertext, to multiple points across the Internet.
HTML evolved from SGML (Standardized Generalized Markup Language, 1986), originally created as GML (General Markup Language) by IBM in the late 60's. HTML is an application of SGML, and facilitates data exchange through a common document format across different types of computer systems and networks on the web.
Hypermedia is an extension of hypertext, and includes images, video, audio, animation and other multimedia types, which can be incorporated into HTML documents. The web is a hypermedia system.
HTML files are plain text files that have been «marked up» with special language elements called tags, which are embedded in the text. Tags are pieces of text, enclosed in angle brackets, that provide instructions to programs designed to interpret HTML.
Good HTML coding practices involves ensuring that content is rendered appropriately regardless if which browser is used.
The HTML standards defines the individual elements that make up the language. The standards include six versions: 1.0, 2.0, 3.0, 3.2, 4.0 and 4.1.
W3C controls the evolution of HTML.
- HTML 1.0
First version of HTML used for graphical browsers. Support for images. - HTML 2.0
Included support for input fields. - HTML 3.0
Was never ratified and evolved directly into HTML 3.2. - HTML 3.2
Introduced features such as tables and frames. - HTML 4.0
Introduced support for:- Stylesheets
- Internationalization features (e.g. reading right to left)
- Accessibility features
- Enhanced tables and forms
- Scripting and multimedia
- HTML 4.0 Transitional
Allows you to use deprecated tags and attributes - HTML 4.0 Strict
Should be used if you want to keep your document focused on the structural markup at the core of HTML, leaving it free of any tags associated with layout. - HTML 4.0 Frameset
Used only for frameset documents.
- HTML 4.01
Includes a few minor modifications, and calls for support of XHTML
XHTML is a combination of XML 1.0 and HTML 4.01. XHTML will allow XHTML-compliant documents to be used, viewed and validated by both HTML and XML processors.
Deprecated tags and attributes are those that have been replaced by other HTML elements and might become obsolete. It is strongly advised not to use deprecated tags.
Tags are deprecated each time a new recommendation becomes a standard. The HTML 4.01 recommendation deprecated many text-formatting tags because stylesheets will handle most text-formatting options.
Deprecated tags include:
- <isindex>
- <applet>
- <center>
- <font>
- <basefont>
- <strike>
- <u>
- <dir>
- <menu>
You can still use deprecated tags, most browsers still support them.
One of the difficulties of deprecated tags, is that some browsers may not support the new tag that replaces the deprecated one. For example, <applet> has been deprecated in favor of <object>. But Netscape navigator, as late as 4.7 do not support the <object> tag, therefor it is still necessary to use the <applet> tag even a few years after the W3C has deprecated it.
Extensions to HTML are proprietary tags that are not a part of any standard. They will only work in certain browsers. These include <blink>, which only works in Netscape and <marquee>, which only works in Internet Explorer. Do not use!
