HTML, XHTML & CSS

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Part VI: The Part of Tens
Although you’re building documents, it’s easy to forget to use closing tags,
even when they’re required (for example, the that closes the opening
anchor tag ). When you’re testing Web pages, some browsers can compensate
for such errors, leaving you with a false sense of security.
The Web is no place to depend on the kindness of strangers. Scrutinize your
tags to head off possible problems from browsers that might not be quite
so understanding (or lax, as the case may be). Validation (using http://
validator.w3.org) is always a good idea, too!
As for claims that some HTML authoring tool vendors make (“You don’t have
to know any HTML!”), all we can say is, “Uh-huh, suuurre. . . .” HTML is a big
part of what makes Web pages work; if you understand it, you can troubleshoot
with minimal fuss. Also, only you can ensure that your pages’ inner
workings are correct and complete, whether you build them yourself or a
program builds them for you.
We could go on and on about this, but we’ll exercise some mercy and confine
our remarks to the most pertinent items:
✓ Keep track of tags yourself while you write or edit HTML by hand. If
you open a tag — be it an anchor, a text area, or whatever — create the
closing tag for it right then and there, even if you have content to add.
Most HTML editors do this for you.
✓ Use a syntax checker to validate your work during the testing process.
Syntax checkers are automatic tools that find missing tags or errors. Use
these syntax checkers whether you build pages by hand or with software.
The W3C’s (free) validator lives at http://validator.w3.org.
✓ Test pages with as many browsers as you can. This not only alerts you
to missing tags, but can also reveal potential design flaws or browser
issues (covered in the later section, “Do Avoid Browser Dependencies”).
This exercise also emphasizes the need for alternate text. That’s why we
check our pages with Lynx (a character-only browser). Ask friends, colleagues,
and co-workers to check out your work, and tell them to use as
many browsers as they can, too. Please!
✓ Always follow HTML document syntax and layout rules. Just because
browsers don’t require elements such as , , and
doesn’t mean you can omit them. It means browsers don’t care whether
you use them or not. But browsers per se are not your audience. Your
users (and future browsers) may indeed care.
Although HTML isn’t exactly a programming language, it makes sense to treat
it like one. Following formats and syntax helps you avoid trouble, and careful
testing and rechecking of your work ensures a high degree of quality, compliance
with standards, and a relatively trouble-free Web site.