Yeah, giving these certs/keys actual names, like from the names of animals, or atomic elements, or characters from one's favorite sci-fi series, or whatever might make the most sense. (And might help mitigate the thought some might have that getting intermediate "6" is newer or more improved in some way than intermediate "5" when it's really just based on which data center processed the request in some way.) Let's Encrypt already seems to like naming projects after things from nature (between "Boulder", "Oak", "Sapling", and recently "Hickory"); I certainly wouldn't be opposed to naming certificates after types of trees or types of rocks or whatever as well.