Even the most simple machines have thoughts. Or at least, I can understand them. They're dumb as fuck and can cause problems during a machine because they're terrible at lying, but they still have personalities. At least in my world, anyway.
My designation is 'Sec Unit'. If there are multiples, then I'd be 'Sec Unit X' with X being a number. I chose Murderbot a few years ago. I've never gone by it totally before now, but I've allowed my friends to call me it. Some don't approve, but I don't care. It's not their name.