The following is the added proviso to what are the institutes of Consecrated Life in the Catholic Church, per the eremitic life. Canon Law 603 [cited below] provides an option for a consecrated Catholic hermit.
Canon Law 603
Can. 603 §1. In addition to the institutes of consecrated life, the Church recognizes the eremitic or anchoritic life by which the Christian faithful devote their life to the praise of God and the salvation of the world through a stricter withdrawal from the world, the silence of solitude, and assiduous prayer and penance.
§2. A hermit is recognized by [Church] law as one dedicated to God in consecrated life if he or she publicly professes in the hands of the diocesan bishop the three evangelical counsels, confirmed by vow or other sacred bond and observes a proper program of living under his direction.
CL603 has some additional requirements beyond what all consecrated Catholic hermits must live per the institutes of the Catholic Church. [See previous post for Consecrated Life in the Church, and specifically The Eremitic Life, 920, 921.] CL 603 requires the Catholic hermit to publicly profess the three evangelical counsels [celibacy, poverty, and obedience] in the hands of his or her diocesan bishop.
Note that the hermit under CL603 proviso must live what is ostensibly determined to be a proper program under the diocese bishop's direction.
Research reveals that in current practice (de facto), many diocesan bishops delegate their direction of said hermit to a priest, deacon, or other designee.
(In these cases, it is presumed that the diocese bishop who received the hermit's professed counsels and who recognized by [Church] law, the hermit's profession, is yet ultimately responsible by church law (de jure, if term technically applicable to church law) for the direction of said hermit. It is also assumed per church law re. the office of bishop, that when a diocesan bishop of legal record is replaced by another bishop, the hermit must then live the determined proper program under the incoming bishop's direction.)
Canon Law 603, while more recent, is a viable, additional provision to the institutes of the Church per consecrated, eremitic life, for the Catholic man or woman discerning and/or called by God to the consecrated life of the Church as an eremitic. For some bishops and hermits, it may be a preferred provision for various reasons, not mentioned here.