Is there such a thing as forbidden bound-free atomic transitions?

[Aoife973]

So I've been studying forbidden transitions and metastable states in atoms, etc., and I was just wondering if there is such a thing as forbidden bound-free transitions? I've only encountered bound-bound.

For example, if you have a neutral Helium atom with two electrons, I understand how forbidden transitions arise within that ion. But are there certain energy levels for which the transition to the ionised state is forbidden?

Thanks for any information! I tried googling but wasn't able to figure it out.

 

[Simon Bridge]

Welcome to PF;
It can help to concentrate on what the terms are actually describing.
"Forbidden" transitions are not actually forbidden forbidden since they can happen.

What exactly it it about the transition that is forbidden?