There are a number of tags that have been removed from HTML 5 that were a part of HTML 4. Let's take a look at what tags these are and what you should be doing instead.
As you can see from the fact that there are only three tags that have actually been removed from HTML 4 in creating HTML 5 the cleanup job that was done in creating the HTML 4 standard where a much larger number of tags were removed came very close to getting things right in so far as deciding what tags should not have been added to HTML in the first place.
If you are wondering about all of the tags that I haven't listed that are not in HTML 5 but which you have been isung with your HTML 4 transitional pages, the reason I haven't listed those tags is that they are the ones that were deleted from HTML 4. There were so many tags deleted from HTML 4 though that it was considered unreasonable to expect everyone to rewrite their pages to not use them straight away and that was what the transitional doctype was created for. HTML 4 transitional allows both HTML 3.2 and HTML 4 tags to be used in the same web page. Those tags which are a part of HTML 3.2 which are not a part of HTML 4 (and which you were supposed to be trying to replace in transitioning to HTML 4) are the ones that are marked as deprecated in any list of HTML 4 tags that you might see. Deprecated means that it is not a part of the HTML 4 standard but is supported for the purpose of transitioning your page from HTML 3.2. That so many people still write pages filled with HTML 3.2 tags rather than writing correct HTML 4 pages just shows how long it is likely to be even after the HTML 5 proposal is finished before most people actually start to use it. At the time of writing this it still looks like the adoption of HTML 4 is many years in the future.
This article written by Stephen Chapman, Felgall Pty Ltd.