<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3c.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3c.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Frameset//EN" "http://www.w3c.org/TR/xhtml1/DTD/xhtml1-frameset.dtd">
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML Basic 1.0//EN" "http://www.w3c.org/TR/xhtml1/DTD/xhtml1-basic10.dtd">
<html xml:lang="en"> </html>
<!-- comments -->
<!-- or comments
on
multilines -->
Each XHTML tag must have a closing tag. For those empty tags in html a forward slash is added as in &ly;br/>. And remember to nest tags properly.