When has an orchid "bloomed" for naming purposes?

[MateoinLosAngeles]

I wonder when a hybrid is considered "in bloom" for registration purposes. I have this new hybrid that has a flower bud currently opening up, I would say halfway through. I didn't buy it in bloom or in spike, it grew the spike fully under my care. It would be cool if I got to name it but who's technically the first person to make an orchid bloom?

In my mind "blooming" is when the bud has visibly fully opened into a flower but I'm not sure if the RHS might have different definitions. I don't seem to find them though. How do you know that a bloom has "fully opened" if you've never seen this flower before?