Deprecated HTML elements still work

Question

W3C has announced that several elements have become deprecated, such as <font>, <frameset> and <strong>, most of which can be replaced by CSS. This change was said to be brought about in HTML 5, however, if I put the HTML 5 doctype on a document these elements still seem to work. Am I unknowingly not actually applying the HMTL 5 doctype, or am I just completely misinterpreting the W3C's notice?

Answer 1

The DOCTYPE does not determine what elements will be supported. If your browser supports an element, than the element will 'work'. Browsers support elements that are deprecated, because they have to work well when they are used to view old sites.

As a thought experiment, what do you think this code will do?

bluefire {
    display: block;
    padding: 1em;
    border: 2px solid black;
}

<bluefire>
    Hello world!
</bluefire>

The definition of whether or not elements 'work' is not clear cut.

Answer 2

Deprecated in this case means that the features remain but their use may raise warning messages recommending alternative practices, and deprecation may indicate that the feature will be removed in the future.

Basically try not to use as there are better alternatives http://en.wikipedia.org/wiki/Deprecation