Need help with Vogue Couturier Pattern #631

Not sure exactly which heading this should be under so, please move it if I picked wrong.

I recently got this nice pattern http://www.mainstreetmallonline.com/patterns/listingview.php?num=29055&ref=15

But it calls for a 12" dress fastener.  Does anyone know what that means?  The directions describe making something like a hidden zipper flap to go over the fastener but I don't know if a zipper is an acceptable substitute. 

Thanks a bunch for your help,
Kristin

Hi all, just fyi several people I contacted said that this is a zipper without calling it a zipper a simple fix.  much thanks