Cascading Style Sheets
Introduction Continued

Rules for XHTML not to be confused with CSS

Open with the proper DOCTYPE & Namespace Declaration

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd ">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">

Write all tags in lowercase

Quote all attribute values

Close all tags

Close “empty” tags, too