I just found out because I'm about to adopt a fluffy gray cat that apparently used to be feral as well; cat rescuers clip the ear when they trap the cat and "fix" it, so they can see at a glance that the cat was already altered and doesn't have to be opened up again.
This is Fifi, and she's at an animal-rescue place called "Li'l Monsters" that's very close to my home; this afternoon, I brought my dog over to when I went to see their available animals. I asked to see their oldest cat, and they introduced me to Fifi. I asked to see the oldest cat in the place because I wanted a cat that wouldn't take any shit from dogs, and they said she often made friends with dogs, but always knew how to tell them when they were crossing the line. When they brought her out of the area, Corky tried to make her run the way he makes Tripod run, and she swatted at him—a very good sign. "That's my cat," I said. I think she'll be great to have in the home, and maybe Tripod will learn to take it easy around Corky; after all, he's made friends with dogs in the past. And Corky only chases him because he runs; if he didn't run, Corky would know better.
And interestingly enough, Fifi likes to go for walks; I don't think I'll ever get to the point where I can take her out with Corky, but apparently having been a feral cat, she longs for the outdoors—in small doses, anyway—so they sometimes take her out on a little harness. Cute!