+ (case format
+ ((:xhtml11 :xhtml)
+ (lml-write-string +xhtml11-dtd-string+))
+ (:xhtml10-strict
+ (lml-write-string +xhtml10-strict-dtd-string+))
+ (:xhtml10-transitional
+ (lml-write-string +xhtml10-transitional-dtd-string+))
+ (:xhtml10-frameset
+ (lml-write-string +xhtml10-frameset-dtd-string+))
+ (:html
+ (lml-write-string +html4-dtd-string+)))
+ (lml-write-char #\newline))