This question and its answer reminded me a question I wondered about a long time ago: the ritual of entering catechumenate usually takes place some time during the process of pre-baptismal catecheses (i.e. learning the basics before someone is prepared for baptism), so there is some time (often quite a long time) when the person is being instructed but didn't enter catechumenate yet.
My question is whether the person is considered a catechumen by canon law since the moment the process of pre-baptismal catecheses begin (may be hard to find out when did it begin!), or since the ceremony of entering the catechumenate? If the latter is the case, have those learning so that they could be baptized any special status?