Should we use strict doctype if our code is valid with Transtional doctype?

Question

What are cons to use transitional doctype with presentational or deprecated element, if our code is valid in W3C validation with transitional doctype?

Will we have to rewrite/edit site's code again after few years for the site's in which we are using XHTML/HTML transtional doctype.?

This is not semantic but using less character, and it wold be good in to use web based WYSIWYG editor in CMS

small {font-size:9px}

<p>hello <small>how</small> are you?</p>

but this using more character

.small-text {font-size:9px}

<p>hello <span class="small-text">how</span> are you?</p>

both will be validated and both has support in all current browsers. but what will be the best for future and why?

Answer 1

So long as you specify the transitional doctype, rather than simply using the transitional elements, I don't think you'll run across any great issues unless the browsers themselves start to drop support for those elements. It's also worth noting that you may be limiting yourself as regards which elements you can use as the transitional doctype is likely to remain static as the strict doctypes evolve.

I don't think you're facing any huge issues, though, certainly not inside of a few years. And most sites, certainly commercial, would probably need to be revised -if only for marketing/branding reasons- before the use of transitional becomes a problem.