HTML QUICK REFERENCE (HTML 3.02)

Created 2/24/98

NOTE: HTML tags are not case-sensitive
<html> . . . </html>
Must be at the beginning and end respectively of every HTML document.
<head> . . . </head>
Identifies the beginning and end of a block of header info.
<title> . . . </title>
Included within the header. Identifies the current HTML page in the titlebar of most browsers.
<body> . . . </body>
Identifies the beginning and end of most of the content of a web page. Not absolutely necessary in all browsers, but strongly recommended.
Attributes:
bgcolor
This attribute allows you to set a default background color which overrides the browser default. Values are six-digit hexadecimal, RGB values where #000000 is black, #ffffff is white, etc. A typical tag for setting background color is
<body bgcolor=#ffffff>.
text
Allows setting of a default color for text in the page. For example,
<body text=#0000ff>.
<a href="http://www.cscs.umich.edu">Highlighted link text</a>
Hypertext link anchor. To link to another web page, use href="http:// ". To link to an email address, use href="mailto:someone@somewhere.edu".
<p>
Creates a line break and starts a new block paragraph. <p> does not need to be followed by </p>.
<br>
A general line break tag. Can be nested inside most other HTML tags and causes most browsers to start a new line.
<blockquote> . . . </blockquote>
Used to offset a quote from preceding and following text. Usually display as a blank line followed by the tagged text, indented a few spaces.
<div> . . . </div>
Encapsulates the group of page elements which follow the initial <div> and allows a single alignment to be given to those elements with the align attribute, with values left, center, right.
<li>
Signifies a list item. Does not require a closing </li> tag. List items can be members of ordered or unordered lists, described below. Both types of lists allow nesting of one list inside another list.
<ul> . . . </ul>
Encapsulates an unordered list (i.e., a list with bullets instead of numbers).
<ol> . . . </ol>
Encapsulates an ordered list (a numbered list).
<dl> . . . </dl>
Defines a definition list, which lists dictionary terms ( <dt> ) followed by dictionary definitions ( <dd> ) which appear on a new line, indented to the right. Definition Lists can also be nested one inside another.
<h1> . . . </h1>
The heading level 1 tag. Causes all text encapsulated by <h1>. . .</h1> to be displayed in a browser in a large, heading style font. There are progressively smaller heading styles from <h2> to <h6>.
<DFN>
for a word being defined. Typically displayed in italics. (NCSA Mosaic is a World Wide Web browser.)
<EM>
for emphasis. Typically displayed in italics. (Consultants cannot reset your password unless you call the help line.)
<CITE>
for titles of books, films, etc. Typically displayed in italics. (A Beginner's Guide to HTML)
<CODE>
for computer code. Displayed in a fixed-width font. (The <stdio.h> header file)
<KBD>
for user keyboard entry. Typically displayed in plain fixed-width font. (Enter passwd to change your password.)
<SAMP>
for a sequence of literal characters. Displayed in a fixed-width font. (Segmentation fault: Core dumped.)
<STRONG>
for strong emphasis. Typically displayed in bold. (NOTE: Always check your links.)
<VAR>
for a variable, where you will replace the variable with specific information. Typically displayed in italics. (rm filename deletes the file.)
<B>
bold text
<I>
italic text
<TT>
typewriter text, e.g. fixed-width font.
<hr>
Defines a horizontal rule with default attributes. Goes from the left margin to the right. Attributes:
size=x
Defines the thickness of the rule as x pixels.
noshade
Removes the default 3D shading that many browsers apply to horizontal rules.
width="x%"
Specifies the horizontal width of the rule, as a percentage of page size.

A good starting guide for learning HTML, which also contains definitions for tags that are not defined in this (incomplete) document is The NCSA Beginner's Guide to HTML.

There is also a more detailed version of this reference page, the HTML Reference Page.