In times of the old german national license, taking only the "normal" theory exam limited you to flying in greater europe including the Canary Islands. To fly longhaul, you needed to take an additonal theoretical exam (longrange theory) which comprised four subjects like longrange flightplanning and general navigation etc. With the introduction of JAR, the topics of these subjects have been merged into the normal theoretical examiniation, so taking now the ATPL Theory Exam gives you a full theory credit including the old longrange theory.
To cut a long story short: if you have a JAA license, you fulfill the requierements they are looking for. Actually the requierement is only of interest to older german pilots who still have the old national license, as it wasn't mandatory to take this exam but now it is as you can't get a JAA license without one.