As the following code and transcript demonstrate, translate-logical-pathname appears to be downcasing paths inconsistently: ;;; test.cl (setf (logical-pathname-translations "foo") '(("foo:bar;*.lisp" "/FooRoot/bar/*.lisp") ("foo:*.lisp" "/FooRoot/*.lisp"))) ;;; In the following pathname translation, the entire path is downcased (pprint (translate-logical-pathname "foo:bar;foobar.lisp")) ;;; In each of the next two, the entire path EXCEPT for the host is downcased -- ;;; the host is unchanged (pprint (translate-logical-pathname "foo:foobar.lisp")) (pprint (translate-logical-pathname "foo:Foobar.lisp")) --- Armed Bear Common Lisp 0.24.0 Java 1.6.0_22 Apple Inc. Java HotSpot(TM) Client VM Low-level initialization completed in 0.478 seconds. Startup completed in 1.386 seconds. Type ":help" for a list of available commands. CL-USER(1): (load "test.cl") #P"/fooroot/bar/foobar.lisp" #P"/FooRoot/foobar.lisp" #P"/FooRoot/foobar.lisp" T CL-USER(2): --- SBCL and CLISP both produce the following output for the above code: #P"/FooRoot/bar/foobar.lisp" #P"/FooRoot/foobar.lisp" #P"/FooRoot/foobar.lisp" Allegro's ALISP and MLISP both produce the following: #P"/FooRoot/bar/foobar.lisp" #P"/FooRoot/foobar.lisp" #P"/FooRoot/Foobar.lisp"