You know that line started selling in 2010, right? The iPhone line has been standard from 2010 as well. iPhone 4, iPhone 4S, iPhone 5, iPhone 5S. The iPhone 5C is a variant of the parent. I'm pretty sure the next one will be the iPhone 6. Looks like convention to me. This naming convention actually started with the 3G and then 3GS. When did Samsung start the "S" line? After the 3GS. Coincidence?