Difference between UC-E17 and UC-E6 USB cables

My Fujifilm x100s, my earlier Nikon D7100, and my new Nikon D750 don’t have a micro or mini USB connectors on them. Hence one needs to use a special cable. While Fuji just calls it as an USB cable, Nikon has fancy names for these cables. The names of the USB cables that come with different camera models of Nikon also vary. For example, the cable that comes with Nikon D7100 is called UC-E17 while the one with D750 is called UC-E17. Is there any difference between the two? Apparently not. I used UC-E6 on D750 and UC-E17 on D7100. Both the camera has responded well. Even my Fuji x100s worked with both the cables. I did not find any links online that could explain the differences among the USB cables of Nikon (there is also an UC-E16!). I did not do any tests related transfer rates on any of the cameras. I am happy as long as I can transfer the files. So, if you’re looking for an extra cable to use with any of these cameras, just grab the one that is the cheapest ( UC-E17 /16 or 6) in your favourite online store.