Why Not XHTML Transitional

XHTML Transitional is just that—a transition. It is designed to help developers
make the move from one technical standard—HTML 4—to another technical
standard—XHTML (Strict). This is a great learning step if you’re stuck in
your HTML 4 ways, but it shouldn’t be seen as an ultimate goal. The difference
between the Transitional XHTML and Strict XHTML is nothing more than the former
allowing more tags and attributes than the latter. This might sound preferable,
but in the long run it’s not. XHTML Strict strips out most of the presentational
crap that we’re trying to get away from. By applying XHTML Strict we are helping
to ensure that there is as little presentational junk in the markup as possible.
One increasingly unjustifiable reason why developers might opt for Transitional
XHTML is if they have a need to accommodate older, rarely used browsers. Presentational elements might result in better presentation in browsers such as
Netscape 4 but using such elements will be detrimental to the efficiency, and
possibly accessibility, of your web pages.
Another reason might be if you are working with other, less knowledgeable
people, or even completely handing over your code to someone (such as a client)
who wants to add/alter/mangle it as they please. But in these cases, there’s not
much point in having a doctype at all (because, remember, quirks mode is for
people who don’t know what they’re doing).
In fact, Transitional XHTML only makes sense when you don’t have complete
control over what you’re doing. If you’re not starting from scratch, or if you have
to accommodate certain foibles or the whims of naïve project managers, for
example, then you might not have much choice. And if you can use a doctype
(and validate to it), it’s better to use something than nothing at all.
But for the sake of argument, let’s assume that we’re not going to be handing
over our Da Vinci to a manic toddler with a pack of crayons. Let’s assume that
we do have complete control over what we’re doing (or at least striving to apply
the highest standards). And let’s assume that the best approach to web design
is to completely separate structure and presentation (because, well, it is). And so
let’s assume that Strict XHTML is the way to go.