The XHTML Transitional Document Type is one of the three XHTML DocTypes.
- XHTML Transitional DocType
- XHTML Strict DocType
- XHTML Frameset DocType
- HTML also has three Document Types: Transitional, Strict, and Frameset.
The Document Types were created to set guidelines for correct XHTML markup coding. These are "Rules" that you can follow to validate your page, to make sure you are righting "Correct" XHTML.
Any page can be assigned to a Document Type by typing in a !DocType tag in the very first line of an HMTL / XHTML document, like this one:
<!DOCTYPE HTML PUBLIC '-//W3C//DTD XHTML 1.0 Transitional//EN' \'http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd\'>
This !DocType is for XHTML Transitional.
Although it is assigned to the Document Type, that does not mean it complies with it's rules.
To see if it complies with the rules, send a link to the document (URL's only, no local files) at the official validation website. [ http://validator.w3.org/ ]