regarding warrior cat names

[peaches]

is it absolutely necessary for a clan cat to have a prefix and a suffix?
the books didn't necessarily have all warriors change their name to the usual kind, like millie. i was wondering if i could do the same, but the cat wasn't any blood but clan.
is it possible or no?

[doghouse]

peaches
I'm not entirely sure, but I do believe that they don't have to change their names. But I don't think this was mentioned in the rules. But you should be able to have a non Clan cat join a Clan and keep their original name.

[Hexict]

is it absolutely necessary for a clan cat to have a prefix and a suffix?
the books didn't necessarily have all warriors change their name to the usual kind, like millie. i was wondering if i could do the same, but the cat wasn't any blood but clan.
is it possible or no?

I'm unsure if I read this part of your question wrong... are asking if a clan-born cat can have a kitty-pet/loner name? If you are then that doesn't make sense since if they were clan-born then they would have a clan name at birth and therefore would have a name with both a prefix and a suffix.

If you are not asking that and just questioning whether a kitty-pet/loner can keep their name upon joining the clan then I believe that they can. There is no rule against it, and there are people that don't change their characters name after they join the clan - most of the time they do change their name, but they can keep it if they wish~

[Crow]

it depends on the leader- it'd be best to ask the respective one of whatever clan you're planning to join.