How Many Document Types Defined in XHTML 1.0?

There are only 3 document types are defined in XHTML 1.0:

1. Strict type: Only allow non-deprecated and non-frameset XHTML elements in this type. Strict type should be declared as below:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
 "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">

2. Transitional type: Allow all XHTML elements defined in "strict" type, plus other elements that are deprecated in HTML 4.0. Transitional type should be declared as below:

<!DOCTYPE html 
 PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
 "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

3. Frameset type: Allow all XHTML elements defined in "transitional" type, plus frame related elements. Transitional type should be declared as below:

<!DOCTYPE html
 PUBLIC "-//W3C//DTD XHTML 1.0 Frameset//EN"
 "http://www.w3.org/TR/xhtml1/DTD/xhtml1-frameset.dtd">

⇒ Smallest Valid XHTML 1.0 Document

⇐ Top Level Structure of XHTML 1.0 Documents

⇑ Introduction of XHTML 1.0

⇑⇑ HTML Tutorials