(a) Housing accommodations subject to the RSL and this Code may be occupied in accordance with the provisions and subject to the limitations of section 235-f of the Real Property Law.

(b) The rental amount that a tenant may charge a person in occupancy pursuant to section 235-f of the Real Property Law shall not exceed such occupant's proportionate share of the legal regulated rent charged to and paid by the tenant for the subject housing accommodation. For the purposes of this subdivision, an occupant's proportionate share shall be determined by dividing the legal regulated rent by the total number of tenants named on the lease and the total number of occupants residing in the subject housing accommodation. However, the total number of tenants named on the lease shall not include a tenant's spouse, and the total number of occupants shall not include a tenant's family member or an occupant's dependent child. Regardless of the number of occupants, tenants named on the lease shall remain responsible for payment to the owner of the entire legal regulated rent. The charging of a rental amount to an occupant that exceeds that occupant's proportionate share shall be deemed to constitute a violation of this Code.