- XHTML 1.1
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
- XHTML 1.0 Strict - Frames and deprecated HTML tags and attributes are not allowed. Must be XML compatible.
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
- XHTML 1.0 Transitional - Allows the use of deprecated HTML tags and attributes. Frames are not allowed. Must be XML compatible.
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
- XHTML 1.0 Frameset - Allows the use of frames and deprecated HTML tags and attributes. Must be XML compatible.
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Frameset//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-frameset.dtd">
- HTML 1.0 Strict - Frames and deprecated HTML tags and attributes are not allowed.
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
- HTML 1.0 Transitional - Allows the use of deprecated HTML tags and attributes. Frames are not allowed.
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
- HTML 1.0 Frameset - Allows the use of frames and deprecated HTML tags and attributes.
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Frameset//EN" "http://www.w3.org/TR/html4/frameset.dtd">
NOTE: There are more DTDs to choose from, but these should be sufficient.