There are two methods to register 4D Client: 4D Client can automatically be registered when connecting or through programming. The easiest way of registering the 4D Client is to use the option in the Preferences. Under the prefereces, go to Client-Server/Configuration. There is an option "Register Clients at Startup for Execute on Client". When this option is checked, each 4D Client connecting to the database is automatically referenced with 4D Server. A process named according to the client machine is created on the server, in the user process group. A process is also created on each client machine.

The second option is to register 4D Client through programming. You can register one or several 4D Client using commands. The "REGISTER CLIENT" command allows you to register a client machine under any name. You can find the documentation for this command at:
https://www.4d.com/docs/CMU/CMU00648.HTM.