Parent with residence

[Notmyyearthisyear]

I’ve heard this term being used a lot but if my understanding is right this is not always applicable.
What happens if both parents share 50/50, is there still a ‘parent with residence’? Any insight into this would be much appreciated!

If it's 50/50 then it's shared care

So whose address would appear on all the child related documentation etc.?

The person whose name is on the child benefit claim