Document Structure Tags Notes
HTML 2.0
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 2.0//EN">
HTML 3.2
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN">
Unicode
A universal character set designed to support all written languages, as well as scholarly disciplines (e.g., mathematics).
xmlns
If your content needs to conform to XHTML, then specify the XML namespace attribute The default entry is xmlns="http://www.w3.org/1999/xhtml".
The <head> Tag
The <head> and </head> tags encompass several page elements, including: a. The <meta> tag. b. The <link> tag that references a CSS file, if present. c. The <title> tag.
<html> tag
The <html> tag is used as a container for the entire HTML document. It nests all code except for the <!DOCTYPE> declaration.
The <meta> Tag
The <meta> tag can specify various information, or metadata, about the document.
character set
The group of symbols used to render text on a page.
<head> tag
The head section allows you to insert <meta> tags (which describe the nature of the document), links to style sheets, and the <title> tag.
content
When paired with the name attribute, the content attribute values can supply keywords, author name, page descriptions and so forth, as previously described.
HTML5
<!DOCTYPE html>
<link> tag
<link> tag — The <link> tag references a style sheet and is recommended for HTML5. A style sheet usually has a .css file name extension and a file name similar to the page to which it is linked (e.g., syb.css for the HTML page named syb.html). Style sheets are often placed in a subdirectory for the Web page. This subdirectory contains all images and associated files for the page. The <link> tag is placed within the <head> container tags.
Document Type Declaration
A declaration of document or code type embedded within an HTML, XHTML, XML or SGML document; identifies the version and markup language used. Denoted by the <!DOCTYPE> declaration at the beginning of the document.
<!DOCTYPE> declaration
The <!DOCTYPE declaration is the first tag in an HTML document. It informs the interpreter (usually a Web browser) what version of HTML the Web page is written in. Previous to HTML5, the <!DOCTYPE> declaration was an SGML statement and required a fairly complex declaration. In HTML5, however, the tag is written as only <!DOCTYPE html>. The declaration is not case-sensitive, but it is almost always written in uppercase letters by Web developers.
<meta> tags
The <meta> tag can specify various information about the document, known as metadata. This metadata can include a document description, revision dates, and keywords to help search engines index the page. It also specifies the HTML5 character set used, which is usually UTF-8. The <meta> tag is placed within the <head> container tags.
<body> tag
This tag begins the body of the document and includes all the content of the Web page, such as the text, video, hyperlinks and images. The <body> tag is placed after the <head> tag.
<title> tag
This tag identifies the document title. Most browsers will display the title in the browser's title bar. The <title> tag is placed within the <head> container tags.
HTML 4.01
a. HTML 4.01 Transitional (<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">) b. HTML 4.01 Strict (<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">) c. HTML 4.01 Frameset (<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Frameset//EN" "http://www.w3.org/TR/html4/frameset.dtd">)
XHTML 1.0
a. XHTML Transitional (<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">) b. XHTML Strict (<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">) c. XHTML Frameset (<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Frameset//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-frameset.dtd">)
Attributes of the <meta> tag include the following:
a. charset b. name c. content
The <html> Tag The opening <html> and closing </html> tags must encompass all markup for the entire page. The <html> tag can include several attributes, including:
a. manifest b. lang c. xmlns
manifest
an attribute used for offline browsing. It lists the address of the HTML document's cache manifest. The manifest attribute requires each page you want cached to include the attribute. This technique is considered more reliable than a traditional browser cache.
lang
configures the page to use a particular language. For instance, a Web document written in English would use <html lang="en"> and a document written in French would use <html lang="fr">. This attribute is helpful for search engines and speech synthesizers. It is a universal attribute that can be used with many different elements besides <html>.
charset
specifies the character set used in HTML documents (which is often set by the Web server for HTML documents, rather than by the document itself). It usually specifies the Unicode character set, which is standard in today's Web pages: <meta charset="utf-8"/>
name
values include "keywords," "description" and "author. " This attribute must be accompanied by the content attribute. The "keywords" value of the name attribute allows you to specify individual words as the value in the accompanying content attribute; these words are used by search engines to match pages to search keywords, and to describe the meaning of the document. The "description" value of the name attribute allows you to specify entire sentences as the value in the accompanying content attribute; these sentences display in search engines to describe the purpose of the document.
