HTML and CSS Reference
compiles a special list of citations from the enclosed text. Similar soft-
ware agents already scour the Internet for embedded information to
compile listings, such as the infamous Google database of web sites.
The most common content-based style used today is that of emphasis,
indicated with the <em> tag. And if you're feeling really emphatic, you
might use the <strong> content style. Other content-based styles include
<code> , for snippets of programming code; <kbd> , to denote text entered
by the user via a keyboard; <samp> , to mark sample text; <dfn> , for
definitions; and <var> , to delimit variable names within programming
code samples. All of these tags have corresponding end tags.
18.104.22.168. Physical styles
Even the barest of barebones text processors conform to a few tradition-
al text styles, such as italic and bold characters. While not word process-
ing tools in the traditional sense, HTML and XHTML provide tags that ex-
plicitly tell the browser to display (if it can) a character, word, or phrase
in a particular physical style.
Although you should use related content-based tags, for the reasons we
argued earlier, sometimes form is more important than function. Use
the <i> tag to italicize text without imposing any specific meaning, the
<b> tag to display text in boldface, or the <tt> tag so that the browser, if
it can, displays the text in a teletype-style monospaced typeface. [ Phys-
It's easy to fall into the trap of using physical styles when you should
really be using a content-based style instead. Discipline yourself now to
use the content-based styles because, as we argued earlier, they con-
vey meaning as well as style, thereby making your documents easier to
automate and manage.