The structure of the topics and key numbers in the American Digest system is modified as needed to reflect developments in the law. Sometimes the modification involves major changes including the creation or elimination of entire topics.
For example, when the new topic HEALTH was created, it replaced former topics:
and absorbed some of the entries from SOCIAL SECURITY AND PUBLIC WELFARE.
Indexes and cases which were published prior to the change will still display the topics and key numbers using the old structure. When you use those old topics and key numbers to look for related cases, it might feel like you are being sent on a wild goose chase.
Suppose you find a reference to HOSPITALS key number 5 in the Descriptive Word Index for West's Federal Practice Digest 4th,
but when you look at the topical volume in the digest for HOSPITALS, there are no entries. At the point in the volume where entries for HOSPITALS should appear, there is a cross reference to "See HEALTH".
You find the volumes for HEALTH, but there are so many key numbers that you're not sure where to begin. That's when you want to use the Key Number Translation Table.
Every topic in West's Federal Practice Digest starts with an outline listing all of the key numbers used in the topics. Some tables may appear after the outline, including Key Number Translation Tables. One table lists the old topics/key numbers and identifies present topics/key numbers relevant to that topic; another table translates the key numbers the other direction.
For example, cases for HOSPITALS key number 5 are now listed in HEALTH key numbers 257, 940, and 961.
Look at the outline for HEALTH to determine the aspects covered by each of the new key numbers. For example, HEALTH key number 257 deals with Records at Institutions and Facilities; HEALTH key number 940 deals with Compensation--Regulation of rates & charges--Hospitals; and HEALTH key number 961 deals with Compensation--Liens--Hospitals.