Just to clarify/re-iterate
There is no 9x18 "Kurtz"
1. There is a round known as the 9mm Kurz, aka 9mm Short, aka 9mm Browning Short, aka 9x17mm, aka .380 auto, aka .380 acp, which measures, yep, 9 by 17mms. It is NOT 9x18. Kurz means, quite simply, "short".
2. Then, there is another round known as the 9mm Makarov, aka 9x18mm, and it measures, yep, 9 by 18mms. And as jak280rem mentioned, this round takes a slightly different diameter bullet (.36 cal) than the other "9mms" (.35 cal)
Then there's the others....