26 CFR §1.465-1T

1. (a)General rule. A partner in a partnership or an S corporation shareholder may aggregate and treat as a single activity—
   1. (1)The holding, production, or distribution of more than one motion picture film or video tape by the partnership or S corporation,
   2. (2)The farming (as defined in section 464 (e)) of more than one farm by the partnership or S corporation,
   3. (3)The exploration for, or exploitation of, oil and gas resources with respect to more than one oil and gas property by the partnership or S corporation, or
   4. (4)The exploration for, or exploitation of, geothermal deposits (within the meaning of section 613(e)(3)) with respect to more than one geothermal property by the partnership or S corporation.
2. (b)Effective date. This section shall apply to taxable years beginning after December 31, 1983 and before January 1, 1985.