26 CFR § 1.509(d)-1
Definition of support
June 25, 2020
For purposes of section 509(a)(2), the term support does not include amounts received in repayment of the principal of a loan or other indebtedness. See, however, section 509(e) as to amounts received as interest on a loan or other indebtedness.
[T.D. 7212, 37 FR 21924, Oct. 17, 1972]