Thursday, December 16, 2010

HTML Inforamtion

The HyperText Markup Language (HTML) is the publishing language of the World Wide Web. The first version of HTML was described by Tim Berners-Lee in late 1991. The current W3C Recommendation for HTML is HTML 4.01, published in December 1999. There is however intensive work to define its next version, HTML5

Version Published year
HTML+ 1993
HTML2.0 1995
HTML3.2 1997
HTML4.01 1999

In HTML 4.0 all formatting can be removed from the HTML document, and stored in a style sheet. Because HTML 4.0 separates the layout from the document structure, we have what we
always needed: Total control of layout, without messing up the document content.

HTML 4.01 Strict
This DTD contains all HTML elements and attributes, but does NOT INCLUDE
presentational or deprecated elements (like font). Framesets are not allowed

HTML5 is a cooperation between the World Wide Web Consortium (W3C) and the Web
Hypertext Application Technology Working Group (WHATWG).
WHATWG was working with web forms and applications, and W3C was working with XHTML
2.0. In 2006, they decided to cooperate and create a new version of HTML.

Some rules for HTML5 were established:
    * New features should be based on HTML, CSS, DOM, and JavaScript
    * Reduce the need for external plugins (like Flash)
    * Better error handling
    * More markup to replace scripting
    * HTML5 should be device independent
    * The development process should be visible to the public

Metadata is information about data.
URL - Uniform Resource Locator
URLs can only be sent over the Internet using the ASCII character-set.
Since URLs often contains characters outside the ASCII set, the URL has to be

converted into a valid ASCII format.
URL encoding replaces unsafe ASCII characters with "%" followed by two hexadecimal
digits corresponding to the character values in the ISO-8859-1 character-set.
ASCII stands for the "American Standard Code for Information Interchange".  It was designed in the early 60's, as a standard character-set for computers and hardware devices like teleprinters and tapedrives.

ASCII is a 7-bit character set containing 128 characters.
It contains the numbers from 0-9, the uppercase and lowercase English letters from A to Z, and some special characters.
The character-sets used in modern computers, HTML, and Internet are all based on ASCII.
The following table lists the 128 ASCII characters and their equivalent HTML entity codes.
ISO-8859-1 is the default character set in most browsers.
The first 128 characters of ISO-8859-1 is the original ASCII character-set (the
numbers from 0-9, the uppercase and lowercase English alphabet, and some special
The higher part of ISO-8859-1 (codes from 160-255) contains the characters used in
Western European countries and some commonly used special characters.

HTML tags are not case sensitive:
means the same as . Many web sites use uppercase HTML tags.
W3Schools use lowercase tags because the World Wide Web Consortium (W3C) recommends
lowercase in HTML 4, and demands lowercase tags in future versions of (X)HTML.

HTML colors are defined using a hexadecimal notation (HEX) for the combination of
Red, Green, and Blue color values (RGB).The lowest value that can be given to one of the light sources is 0 (in HEX: 00). The highest value is 255 (in HEX: FF).
HEX values are specified as 3 pairs of two-digit numbers, starting with a # sign.
The combination of Red, Green, and Blue values from 0 to 255, gives more than 16
million different colors (256 x 256 x 256).
The 17 standard colors are: aqua, black, blue, fuchsia, gray, grey, green, lime,
maroon, navy, olive, purple, red, silver, teal, white, and yellow.

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