Pearse Doherty (Donegal, Sinn Fein) | Oireachtas source

I think this seems straightforward enough but I seek clarification. This allows for a person to elect which parent they choose to benefit from capital acquisitions tax, CAT, whether it be their birth parents or their social parents but it does not allow for a change in that election at any time or to benefit from both. That is my understanding. Is that correct?