Deductions & credits

The instructions in https://www.irs.gov/pub/irs-pdf/f8880.pdf read as follows:

Line 4
Enter the total amount of distributions you, and your spouse if filing jointly, received after 2019 and before the due date of your 2022 return (including extensions) from any of the following types of plans.
• Traditional or Roth IRAs, or ABLE accounts.
• 401(k), 403(b), governmental 457(b), 501(c)(18)(D), SEP, SIMPLE, or the federal TSP.
• Qualified retirement plans, as defined in section 4974(c)

 

My sister's pension is definitely not in the first 2 categories. I researched the last category.  Section 4974(c) reads:

(c) Qualified retirement plan For purposes of this section, the term ‘‘qualified retirement plan’’ means— (1) a plan described in section 401(a) which includes a trust exempt from tax under section 501(a), (2) an annuity plan described in section 403(a), (3) an annuity contract described in section 403(b), (4) an individual retirement account described in section 408(a), or (5) an individual retirement annuity described in section 408(b). Such term includes any plan, contract, account, or annuity which, at any time, has been determined by the Secretary to be such a plan, contract, account, or annuity.

 

My sister's pension is none of those choices. It is a defined benefit plan which is not described above. Given what this is identifying per the IRS information, please explain how her pension is a qualified plan that limits the form 8880 credit as you claim.