Consistency.
(C) Consistency. Generally, all controlled participants in a CSA taking options on publicly traded stock into account under paragraph (d)(3)(ii), (d)(3)(iii)(A), or (d)(3)(iii)(B) of this section must use that same method of identification, measurement and timing for all options on publicly traded stock with respect to that CSA. Controlled participants may change their method only with the consent of the Commissioner and only with respect to stock options granted during taxable years subsequent to the taxable year in which the Commissioner's consent is obtained. All controlled participants in the CSA must join in requests for the Commissioner's consent under this paragraph (d)(3)(iii)(C). Thus, for example, if the controlled participants make the election described in paragraph (d)(3)(iii)(B) of this section upon the formation of the CSA, the election may be revoked only with the consent of the Commissioner, and the consent will apply only to stock options granted in taxable years subsequent to the taxable year in which consent is obtained. Similarly, if controlled participants already have granted stock options that have been or will be taken into account under the general rule of paragraph (d)(3)(iii)(A) of this section, then except in cases specified in the last sentence of paragraph (d)(3)(iii)(B)(4) of this section, the controlled participants may make the election described in paragraph (d)(3)(iii)(B) of this section only with the consent of the Commissioner, and the consent will apply only to stock options granted in taxable years subsequent to the taxable year in which consent is obtained.