This booklet addresses the fundamentals of securities custody and related services, and provides guidance for examining those activities in national banks. One of a series of specialized asset management booklets in the Comptroller's Handbook, the booklet supplements the overall guidance in the "Asset Management Supervision" booklet as well as the "Large Bank Supervision" and "Community Bank Fiduciary Activities" booklets. For additional guidance on general asset management operations and controls, please refer to the Comptroller's Handbook for Asset Management. Please refer to this booklet's glossary for definitions of terms used in this handbook.