Although the following examples are possible to execute only in implementations which permit :unspecific in the indicated position andwhich permit four-letter type components, they serve to illustrate the basic concept of pathname merging.
(pathname-type (merge-pathnames (make-pathname :type "LISP") (make-pathname :type "TEXT"))) => "LISP" (pathname-type (merge-pathnames (make-pathname :type nil) (make-pathname :type "LISP"))) => "LISP" (pathname-type (merge-pathnames (make-pathname :type :unspecific) (make-pathname :type "LISP"))) => :UNSPECIFIC