What is DOCTYPE?

by

Basically, the DOCTYPE describes the HTML that will be used in your page.

Browsers also use the DOCTYPE to determine how to render a page. Not including a DOCTYPE or including an incorrect one can trigger quirks mode.

The kicker here is, that quirks mode in Internet Explorer is quite different from quirks mode in Firefox (and other browsers); meaning that you’ll have a much harder job, trying to ensure your page renders consistently with all browsers if the quirks mode is triggered, than you will if it is rendered in standards mode.

Wikipedia has a more in-depth summary of the differences in rendering when using various DOCTYPEs. XHTML is enabled by certain DOCTYPEs, and there is quite a bit of debate about the use of XHTML which is covered well in XHTML — myths and reality.

There are subtle differences between different “standards compliant” rendering DOCTYPEs, such as the HTML5 DOCTYPE (<!DOCTYPE html>, prior to HTML5, only known as the “skinny doctype” which does not trigger standardized rendering in older browsers) and other DOCTYPEs such as this one for HTML 4.01 transitional:

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">

More Related Contents:

  1. What are the different doctypes in html and what do they mean?
  2. Redirect from an HTML page
  3. Why can’t the tag contain a tag inside it?
  4. Setting the width of inline elements
  5. Why do browsers insert tbody element into table elements?
  6. How do I link to part of a page? (hash?)
  7. Can an HTML element have multiple ids?
  8. A Space between Inline-Block List Items [duplicate]
  9. display: inline-block extra margin [duplicate]
  10. RegEx match open tags except XHTML self-contained tags
  11. White space at bottom of anchor tag
  12. HTML: Is it possible to have a FORM tag in each TABLE ROW in a XHTML valid way?
  13. What is the functionality of !DOCTYPE?
  14. JavaServer Faces 2.2 and HTML5 support, why is XHTML still being used
  15. Making the main scrollbar always visible
  16. Why do browsers think this tag isn’t immediately ended?
  17. Any reason not to start using the HTML 5 doctype? [closed]
  18. How to make div occupy remaining height?
  19. Where is the HTML5 Document Type Definition?
  20. Tick symbol in HTML/XHTML
  21. HTML5 doctype putting IE9 into quirks mode?
  22. Can comments appear before the DOCTYPE declaration?
  23. Valid content-type for XML, HTML and XHTML documents
  24. Change checkbox check image to custom image
  25. Specifying Tab-Width?
  26. Safari anchors on links not working
  27. Padding the top and the bottom of inline element
  28. Is div inside list allowed? [duplicate]
  29. Why certain DOCTYPE declarations cause 100%-height tables and divs to stop working?
  30. Table vertical header?

Leave a Comment