XHTML

The Body Text is the text contained within the body tags of a webpage.

A Document Type Definition (DTD) is a document that allows a program, such as a web browser, to properly parse a markup language that is formatted according to a specific use. HTML and its XML-based brother XHTML are probably the most common DTDs today, supplying web browsers with the guidelines for properly rendering web page elements.

Further Reading

W3C Definition of DTD