I totally agree with this. There is almost nothing more painful than to see incorrect code being taught.

At my university, all computer/information system majors have to take ITK 160 (Introduction to Computer Concepts). Right now we are on the internet/networking chapters. One day in lecture, we were taught HTML. My God, I wanted to just stop my professor and teach the damn class myself. The PowerPoint slides showed off HTML code being in ALL CAPS, attributes formatted as: attribute_name = value, instead of: attribute_name="value". Image and line break tags were also shown as non-self closing.

It was just such a disgrace to see this.

This was very informative; thanks for writing it.

I just have a question though.... Why exactly are some tags "deprecated"? I know there are other ways to get the same effect like you said, but what's wrong with doing it an old way? I've been using <b > for a while and never knew it was deprecated. >.>

Edit: Gahh, I had a teacher kind of like that. <_< I doubt she even knew or cared what "DOCTYPE" meant, or even noticed it was there. She made us all work strictly with the layout mode where you click and drag boxes to make tables and lectured me when I tried to use Notepad or the code view. I hated that class so much. >_>

I know that in the case of the difference between b/strong and i/em, the latter of the pair work with screen readers. When the screen reader is reading out the text, it puts the correct emphasis on the strong's and em's.

HTML tags written in full caps are the ugliest things ever. :/

To answer your question, Stormy, over time the designers of HTML added new capabilities to the language that are either easier or "more correct" than previous methods, an example of which is using CSS to style instead of various HTML attributes (like height, width, bgcolor, etc.). Thus, these older ways of doing things have been deprecated in favor of the new features of the language.

Actually, using uppercase tag names is perfectly valid in HTML 4.01 and HTML 5. That doesn't mean I won't stab anyone who writes like that, though.

quote

Image and line break tags were also shown as non-self closing.

Self closing tags aren't valid HTML, they're XHTML. They're not the same. HTML is based on SGML, XHTML is based on XML. Self closing tags are valid in (X)HTML 5 and you may mix and match coding styles, but in HTML class where they teach HTML, <br> is correct ;) .

quote

Why exactly are some tags "deprecated"?

Some ideas sound good when they're implemented, but turn out to be unneeded or just plain stupid in the future. In the PHP world, for example, there's something called Register Globals. Sounded neat at first, but nobody in their right mind would advise you to use them now.

Early versions of HTML relied on tags like <b> and <font> for formatting since it was the only way to make your document all pretty and neat. Style sheets are a far better alternative, so now the official advice is: ``Don't use presentational tags, use CSS´´. But you can still use them, for backwards compatibility. <strong> isn't the same as <b>. <b> stands for 'bold', <strong> stands for ``THIS IS REALLY PRETTY IMPORTANT, Y'ALL´´ or somesuch. <em> is emphasize. Most browsers will render them bold and in italic, but they don't need to. If you want, you could change <strong> to 'T H I S' and that wouldn't be wrong. Better than sticking <span>s and <div>s all over the place.

For all of my documents, I use HTML 4.01 Strict and I advise you to do the same. If you must, use XHTML 1.0. IE doesn't really understand XHTML 1.0 (``what are all those funny slashes doing in my <img>?´´ but will render (most of the time) in Standards Mode and not in Quirks Mode.
XHTML 1.1 and 2.0 are useless for the web. 1.1 and 2.0 must be sent to the user agent as 'application/xhtml+xml', 1.0 may, but it isn't mandatory. Browsers that don't support XHTML will prompt you with a download window (``this is an XML file, what am I supposed to do with this?´´ and browsers that do support XHTML may not render your document at all if there is even a slight syntax error. With today's user generated content and editors such as CKEdtor and TinyMCE, that won't do at all.
So HTML 4.01, XHTML 1.0 or HTML 5 (Google.com uses it!) whenever that takes off, since it's backwards compatible.

And I assume everyone here knows about Conditional Comments, right? They're the perfect way of sending IE-only code to browsers in a standards compliant, failsafe, low overhead, JavaScript-free method.

code

<!--[if IE]> You are using Internet Explorer (any version) <![endif]--> <!--[if IE 6]> You are using Internet Explorer 6 <![endif]--> <!--[if lte IE 7]> You are using IE7 or below. <![endif]--> <!--[if !IE]><!--> You are NOT using Internet Explorer! <!-- <![endif]-->

Haven't found a use for the last one, (I only use CCs to include an IE6 CSS file, 7 and 8 are easy enough to handle) but it's so ingeniously genius, I had to mention it.

I agree wholeheartedly with this thread (I got off topic though, and branched off to this thread about javascript).

HTML is ever still, a journey to conquer person to person.

Self-closing tags in HTML versions before 5 are invalid, plain and simple. I personally don't care if they're added, but it's not to spec.

I agree with the notion that uppercase tags should not be used, for readability and consistency. They shouldn't be used, but they're valid HTML. That's exactly what I said in my post.
I personally feel that (for example) CSS classes should always use dashes to separate words and that they should not be CamelCased, but such class names are valid. I also leave off the closing PHP tag (?>), that's valid, but you might not like doing that personally.

quote http://validator.w3.org/docs/errors.html

63: character data is not allowed here

You have used character data somewhere it is not permitted to appear. Mistakes that can cause this error include:
• putting text directly in the body of the document without wrapping it in a container element (such as a <p>aragraph</p>), or
• forgetting to quote an attribute value (where characters such as "%" and "/" are common, but cannot appear without surrounding quotes), or
• using XHTML-style self-closing tags (such as <meta ... />) in HTML 4.01 or earlier. To fix, remove the extra slash ('/') character. For more information about the reasons for this, see Empty elements in SGML, HTML, XML, and XHTML.

Just because the validator doesn't pick it up, doesn't mean it's correct.

In fact, browsers don't even like this. Straight from the Webkit (Safari/ Chrome's render engine) development team:

quote http://webkit.org/blog/68/understanding-html-xml-and-xhtml/

It’s important to note that this is kind of a hack, and depends on the de facto error handling behavior of HTML parsers. They don’t really understand the XML self-closing syntax, but writing things this way makes them treat / as an attribute, and then discard it because it’s not a legal attribute name. And if you tried to do something like <div />, they wouldn’t understand that the div is supposed to be empty.

In short, they handle '<br />' as '<br invalidAttributeParserErrorDangerDanger>'

The above article is pretty interesting, it's not very long.

Well, to be fair, the "invalidAttributeParserErrorDangerDanger" is the behavior of an HTML parser, not an XML parser.

But since most XHTML writers probably aren't serving their documents as the correct MIME type anyway, it doesn't really matter. (And there are many problems with this. See (1), (2), (3).)

PS Yes I stole these links from the webkit blog—very nice article, I must say.