In the Warrior series, there is a unique way of naming in the clans. There is a prefix and a suffix. A cat will keep their prefix their whole life, unless something else happens, but most of the time, they keep their prefix. When a kit is born, they will have a prefix. For example, Black. The kit will take the suffix of -kit, until they become an apprentice. So, our example kit's name would currently be Black'kit. When they become an apprentice, their name will be changed to Blackpaw.
When they become a warrior or medicine cat, their suffix will change to what the leader decides. For example, if the leader chooses for the suffix to be Ice, our example's name would be Black Ice. For another example, Acornkit would turn into Acornpaw, then Acornheart. If the cat eventually becomes leader, they would take the -star suffix, so Acornheart will turn into Acornstar. This is how the naming system works.