12 C.F.R. § 3.211
(b) SSFA parameters. To calculate the specific risk-weighting factor for a securitization position using the SSFA, a national bank or Federal savings association must have accurate information on the five inputs to the SSFA calculation described in paragraphs (b)(1) through (b)(5) of this section.
(2) Parameter W is expressed as a decimal value between zero and one. Parameter W is the ratio of the sum of the dollar amounts of any underlying exposures of the securitization that meet any of the criteria as set forth in paragraphs (b)(2)(i) through (vi) of this section to the balance, measured in dollars, of underlying exposures:
(v) Has contractually deferred payments for 90 days or more, other than principal or interest payments deferred on:
(c) Mechanics of the SSFA. KG and W are used to calculate KA, the augmented value of KG, which reflects the observed credit quality of the underlying exposures. KA is defined in paragraph (d) of this section. The values of parameters A and D, relative to KA determine the specific risk-weighting factor assigned to a position as described in this paragraph (c) and paragraph (d) of this section. The specific risk-weighting factor assigned to a securitization position, or portion of a position, as appropriate, is the larger of the specific risk-weighting factor determined in accordance with this paragraph (c), paragraph (d) of this section, and a specific risk-weighting factor of 1.6 percent.
(3) When A is less than KA and D is greater than KA, the specific risk-weighting factor is a weighted-average of 1.00 and KSSFA calculated under paragraphs (c)(3)(i) and (c)(3)(ii) of this section. For the purpose of this calculation:
(i) The weight assigned to 1.00 equals
