I thought I'd answer a question asked here about non-Catholics receiving the sacrament of reconciliation by using the RCIA book, but in skimming all the steps, there doesn't seem to be much said about confession, I know it's unnecessary for the unbaptized, but don't baptized Christians preparing to be in full communion with the Church have to go to confession first?
Catechumens do not go to confession before reception into the Catholic Church, you were thinking of "candidates for reception" as outlined in Chapter 5 of the RCIA.
Candidates for reception are baptized Christians who express their wish to make a full profession of faith and be received fully into the Catholic Church.
As for their confession,
If the profession of faith and reception take place within Mass, the candidate, according to his or her own conscience, should make a confession of sins beforehand, first informing the confessor that he or she is about to be received into full communion. Any confessor who is lawfully approved may hear the candidates confession.
So, now you can go answer that other question with some impressive minutiae! Go get 'em tiger.