https://www.law.cornell.edu/uscode/text/19/2191
For purposes of this section
(1) The term implementing bill means only a bill of either House of Congress which is introduced as provided in subsection (c) of this section with respect to one or more trade agreements, or with respect to an extension described in section 3572 (c)(3) of this title, submitted to the House of Representatives and the Senate under section 2112 of this title, section 3572 of this title, or section 3805 (a)(1) of this title and which contains
(A) a provision approving such trade agreement or agreements or such extension,
(B) a provision approving the statement of administrative action (if any) proposed to implement such trade agreement or agreements, and
(C) if changes in existing laws or new statutory authority is required to implement such trade agreement or agreements or such extension, provisions, necessary or appropriate to implement such trade agreement or agreements or such extension, either repealing or amending existing laws or providing new statutory authority.
(2) The term implementing revenue bill or resolution means an implementing bill, or approval resolution, which contains one or more revenue measures by reason of which it must originate in the House of Representatives.
(3) The term approval resolution means only a joint resolution of the two Houses of the Congress, the matter after the resolving clause of which is as follows: That the Congress approves the extension of nondiscriminatory treatment with respect to the products of XXXX transmitted by the President to the Congress on XXXX., the first blank space being filled with the name of the country involved and the second blank space being filled with the appropriate date.
The President has to submit a signed treaty for TPA to apply, and the President must submit an implementing bill. A dispute over whether or not a bill qualifies would be referred to the Parliamentarian.