Paragraph (1)(B) shall not apply to any plan maintained pursuant to an agreement between employee representatives and 1 or more employers if the Secretary finds that such agreement is a collective bargaining agreement and that the benefits referred to in paragraph (1)(B) were the subject of good faith bargaining between such employee representatives and such employer or employers.
Paragraph (1)(C) shall not apply to any amount attributable to a contribution to the fund which is not allowable as a deduction under section 419 for the taxable year or any prior taxable year (and such contribution shall not be included in any carryover under section 419(d)).
Subparagraphs (A) and (B) of paragraph (1) shall not apply to post-retirement benefits charged against an existing reserve for post-retirement medical or life insurance benefits (as defined in section 512(a)(3)(E)) or charged against the income on such reserve.
For purposes of this section, the terms used in this section shall have the same respective meanings as when used in subpart D of part I of subchapter D of chapter 1.