FileMaker Pro 4.1 Mac User's Guide

Using data from related files 10-17
For example, in a Client file you might want to assign each client a
unique, identifying number. You wouldn’t enter a client number into
the file unless you had a new client to add, so the existence of a client
number determines the existence of a record.
Client file
Route file Trip file
4. For each file, decide which fields will store data and which ones will
use data from other files.
The fields in each database file all store a single occurrence of the
subject of the database file. For example, the fields in the Client file
(client identification number, name, address, and phone number)
together store all the information about one client. Other data can be
combined as needed from other database files.