(1) A utility shall not require a cash deposit or other guarantee as a condition of new or continued residential utility service based upon commercial credit standards (except as provided in these rules) , income, home ownership, residential location, race, color, creed, sex, age, national origin, or any other criteria not authorized by these rules. This rule does not prohibit a utility from ensuring that agreements with customers who may be incompetent, such as minors, are made in such a manner, and with such persons, as to be legally binding.