WHAT DOES 17 HORNET BRASS MEAN?

I have a Savage seventeen Hornet. It is a very economical little cartridge. I like it but for me a 20 Realistic within an AR has all but changed it.I’ve reloaded Hornady seventeen Hornet brass quite a few instances with no a problem. Incredibly difficult to find, so gotta buy it when discover it. I recognize Graf’s rapidly shipping!Your respons