HTML5 <!DOCTYPE HTML> —————————————————————————————— xhtml 1.1: <!doctype html public "-/w3c/dtd xhtml 1.1/en" "http://www.w3.org/tr/xhtml11/dtd/xhtml11.dtd"> xhtml 1.1 plus mathml plus svg: <!doctype html public "-/w3c/dtd xhtml 1.1 plus mathml 2.0 plus svg 1.1/en" "http://www.w3.org/2002/04/xhtml-math-svg/xhtml-math-svg.dtd"> —————————————————————————————— html 4.01 strict: <!doctype html public "-/w3c/dtd html 4.01/en" "http://www.w3.org/tr/html4/strict.dtd"> html 4.01 transitional: <!doctype html public "-/w3c/dtd html 4.01 transitional/en" "http://www.w3.org/tr/html4/loose.dtd"> html 4.01 frameset: <!doctype html public "-/w3c/dtd html 4.01 frameset/en" "http://www.w3.org/tr/html4/frameset.dtd"> —————————————————————————————— xhtml 1.0 strict: <!doctype html public "-/w3c/dtd xhtml 1.0 strict/en" "http://www.w3.org/tr/xhtml1/dtd/xhtml1-strict.dtd"> xhtml 1.0 transitional: <!doctype html public "-/w3c/dtd xhtml 1.0 transitional/en" "http://www.w3.org/tr/xhtml1/dtd/xhtml1-transitional.dtd"> xhtml 1.0 frameset: <!doctype html public "-/w3c/dtd xhtml 1.0 frameset/en" "http://www.w3.org/tr/xhtml1/dtd/xhtml1-frameset.dtd"> —————————————————————————————— html 3.2: <!doctype html public "-/w3c/dtd html 3.2 final/en"> —————————————————————————————— html 2(数字2代表版本号): <!doctype html public "-/ietf/dtd html 2.0/en">