For the most part, tags—the markup elements of HTML and
XHTML—are simple to understand and use, since they are made up of common
words, abbreviations, and notations. For instance, the
</i> tags respectively tell the browser
to start and stop italicizing the text characters that come between
them. Accordingly, the syllable "simp" in our barebones example in Figure 3-1 should appear italicized
when displayed by the browser.
Figure 3-1. Compare this browser display with its Barebones source HTML shown earlier
The HTML and XHTML standards and their various extensions define how and where you place tags within a document. Let's take a closer look at that syntactic sugar that holds together all documents.
Every tag consists of a tag name, sometimes followed by an optional
list of tag attributes, all
placed between opening and closing brackets (
>). The simplest tag is nothing more than
a name appropriately enclosed in brackets, such as
<i>. More complicated tags contain one
or more attributes, which specify or modify the behavior of the
According to the HTML standard, tag and attribute names are not
case-sensitive. There's no difference in effect between
<HEAD>, and even
<HeaD>; all of them are equivalent.
With XHTML, case is important: all current standard tag and attribute names are in lowercase; always ...