Text Conventions
Throughout the book, we use a constant-width typeface to highlight any
literal element of the HTML/XHTML standards, tags, and attributes. We
always use lowercase letters for tags.[*] We use italic for filenames and to
indicate new concepts when they are defined. Elements you need to supply
when creating your own documents, such as tag attributes and
user-defined strings, appear in constant-width
italic in the code.
We discuss elements of the language throughout the book, but
you'll find each one covered in depth (some might say in nauseating
detail) in a shorthand, quick-reference definition box that looks like
the one that follows (for the <title> element). The first line of the
box contains the element name, followed by a brief description of its
function. Next, we list the various attributes, if any, of the element:
those things that you may or must specify as part of the element.
The icon ‼ identifies tags and attributes that aren't in the HTML 4.01 or XHTML 1.0 standards, and those that are handled very differently between the various popular browsers.
The description also includes the HTML ending tag, if any, for the element, along with a general indication of whether the end tag may be safely omitted in general use in HTML. For the few tags that require end tags in XHTML, but do not have them in HTML, the language lets ...