Hi, this defstruct (defstruct (external-entdef (:include entdef) (:constructor make-external-entdef (extid ndata)) (:conc-name #:entdef-)) (extid (error "missing argument") :type extid) (ndata nil :type (or rod null))) in xml-parse.lisp has a forward reference to the type EXTID which is defined later in the same file. LispWorks doesn't like this (although it only warns and carries on) and I /think/ it is not portable CL, but I'm too lazy to look it up. Cheers, Edi.