What section of the Internal Revenue Code governs charitable lead trusts?

A charitable deduction is allowed for a contribution of an income interest in trust (remainder to a noncharity) onlyif: (1) the donor is taxable on the trust income, and (2) the donated income interest is either a "guaranteed annuity" or a "unitrust interest." (Code Sec. 170(f)(2)(B); Reg § 1.170A-6 )