Hypertext Markup Language
(HTML) A hypertext document format used on the web. HTML is built on top of SGML. "Tags" are embedded in the text. A tag consists of a "<", a "directive" (in lower case), zero or more parameters and a ">". Matched pairs of directives, like "<title>" and "</title>" are used to delimit text which is to appear in a special place or style.
Links to other documents are in the form
where "<a>" and "</a>" delimit an "anchor", "href" introduces a hypertext reference, which is most often a Uniform Resource Locator (URL) (the string in double quotes in the example above). The link will be represented in the browser by the text "foo" (typically shown underlined and in a different colour).
A certain place within an HTML document can be marked with a named anchor, e.g.:
The "fragment identifier", "baz", can be used in an href by appending "#baz" to the document name.
Other common tags include <p> for a new paragraph, <b>..</b> for bold text, <ul> for an unnumbered list, <pre> for preformated text, <h1>, <h2> .. <h6> for headings.
HTML supports some standard SGML national characters and other non-ASCII characters through special escape sequences, e.g. "é" for a lower case 'e' with an acute accent. You can sometimes get away without the terminating semicolon but it's bad style.
Most systems will ignore the case of tags and attributes but lower case should be used for compatibility with XHTML.
The web Consortium (W3C) is the international standards body for HTML.