The recognition of marriage as a very personal act and, sitting on the right to contract it as proclaimed by our Constitution in line with the other international instruments ratified by Spain, as well as the principle ?favor matrimonii? that is it does not permit an ?in-generation? deprivation of the ability to contract it, but that it must be preached abstraction made of the judicial modification of the capacity of the contractor or contenders in the relevant proceedings, as it comes recognizing the recent jurisprudence of the Supreme Court, on the one hand, and the DGRN doctrine, on the other. In this go, the particularities presented by this bilateral legal business of Family Law, advise to pay detailed attention to the subjective requirement of the ability to contract it, an essential condition for the valid celebration which is the biggest problem when the contractor (or contractors) has a disability and/or is incapacitated. At this point, the requirement for a medical opinion by the Person responsible for processing the marriage file provided for in Article 56 of the Civil Code, the recent reform of which has not yet entered into force, has chosen to assign to him, as a mechanism for the pre-control of that capacity, an exceptional and subsidiary nature in the case of persons with a ?serious? disability (second paragraph), as if their requirement were an obstacle that seeks to limit the possibility of contracting marriage for those. While it is true that the legislature has thus sought to seek maximum agreement at this point with the arts. 12.3 and 23.1 of the 2006 Convention, this reform deserves critical considerations that will be the subject of attention in the coming lines.