HTML and CSS Reference
2.5. The Flesh on an HTML or XHTML Document
Except for the <html> , <head> , <body> , and <title> tags, the HTML and
XHTML standards have few other required structural elements. You're
free to include pretty much anything else in the contents of your doc-
ument. (The web surfers among you know that authors have taken full
advantage of that freedom, too.) Perhaps surprisingly, though, there are
only three main types of HTML/XHTML content: tags (which we described
previously), comments, and text.
A raw document with all its embedded tags can quickly become nearly
unreadable, like computer-programming source code. We strongly re-
commend that you use comments to guide your composing eye.
Although it's part of your document, nothing in a comment, which goes
between the special starting tag <! and ending tag > comment delimiters,
gets included in the browser display of your document. You see a com-
ment in the source, as in our simple HTML example, but you don't see
it on the display, as evidenced by our comment's absence in Figure 2-1 .
Anyone can download the source text of your documents and read the
comments, though, so be careful what you write.
If it isn't a tag or a comment, it's text. The bulk of content in most of
your HTML/XHTML documentsthe part readers see on their browser dis-
playsis text. Special tags give the text structure, such as headings, lists,
and tables. Others advise the browser how the content should be format-
ted and displayed.