Subpart A — General Rules for Taxation of Estates and Trusts (Sections 641 to 646)
Subpart B — Trusts Which Distribute Current Income Only (Sections 651 to 652)
Subpart D — Treatment of Excess Distributions by Trusts (Sections 665 to 668)
Subpart E — Grantors and Others Treated as Substantial Owners (Sections 671 to 679)