anchor.diff:          (when (disallow-internal-subset *ctx*)
             (error "document includes an internal subset"))
           (ensure-dtd)
  -        (setf fresh-dtd-p nil)
           (consume-token input)
           (while (progn (p/S? input)
                         (not (eq (peek-token input) :\] )))
  
positive.code:         (let* ((effective-extid
                  (extid-using-catalog (absolute-extid input extid)))
                 (sysid (extid-system effective-extid))
                 (cached-dtd
                  (and fresh-dtd-p
                       (not (standalone-p *ctx*))
  
negative.code: (defun p/doctype-decl (input &optional dtd-extid)
    (let ()
      (let ((*expand-pe-p* nil)
            name extid)
        (expect input :|<!DOCTYPE|)
        (p/S input)
  