Purpose. This section provides rules for applying section 7701(i), which defines taxable mortgage pools. The purpose of section 7701(i) is to prevent income generated by a pool of real estate mortgages from escaping Federal income taxation when the pool is used to issue multiple class mortgage-backed securities. The regulations in this section and in 301.7701(i)2 through 301.7701(i)4 are to be applied in accordance with this purpose. The taxable mortgage pool provisions apply to entities or portions of entities that qualify for REMIC status but do not elect to be taxed as REMICs as well as to certain entities or portions of entities that do not qualify for REMIC status.