26 CFR §1.1092(b)-5T

1. (a)Disposing, disposes, or disposed. The term disposing, disposes, or disposed includes the sale, exchange, cancellation, lapse, expiration, or other termination of a right or obligation with respect to personal property (as defined in section 1092(d)(1)).
2. (b)Hedging transaction. The term hedging transaction means a hedging transaction as defined in section 1256(e).
3. (c)Identified straddle. The term identified straddle means an identified straddle as defined in section 1092(a)(2)(B).
4. (d)Loss. The term loss means a loss otherwise allowable under section 165(a) (without regard to the limitation contained in section 165(f)) and includes a write-down in inventory.
5. (e)Mixed straddle. The term mixed straddle means a straddle—
   1. (1)All of the positions of which are held as capital assets;
   2. (2)At least one (but not all) of the positions of which is a section 1256 contract;
   3. (3)For which an election under section 1256(d) has not been made; and
   4. (4)Which is not part of a larger straddle.
6. (f)Non-section 1256 position. The term non-section 1256 position means a position that is not a section 1256 contract.
7. (g)Offsetting position. The term offsetting position means an offsetting position as defined in section 1092(c)(2).
8. (h)Position. The term position means a position as defined in section 1092(d)(2).
9. (i)[Reserved]
10. (j)Related person or flowthrough entity. The term related person or flowthrough entity means a related person or flowthrough entity as defined in sections 1092(d)(4) (B) and (C) respectively.
11. (k)Section 1256 contract. The term section 1256 contract means a section 1256 contract as defined in section 1256(b).
12. (l)[Reserved]
13. (m)Straddle. The term straddle means a straddle as defined in section 1092(c)(1).
14. (n)Successor position. The term successor position means a position (“P”) that is or was at any time offsetting to a second position if—
    1. (1)The second position was offsetting to any loss position disposed of; and
    2. (2)P is entered into during a period commencing 30 days prior to, and ending 30 days after, the disposition of the loss position referred to in paragraph (n)(1) of this section.
15. (o)Unrecognized gain. The term unrecognized gain means unrecognized gain as defined in section 1092(a)(3)(A).
16. (p)Substantially identical. The term substantially identical has the same meaning as substantially identical in section 1091(a).
17. (q)Securities. The term security means a security as defined in section 1236(c).