New Registrar Feature

What is this CodeIgniter\Shield\Config namespace?

It is just sample code. It is a sample namespace.
Probably in your context, a namespace that you use.

Any namespace may define implicit registrars by using the Config/Registrar.php file. These files are classes whose methods are named for each configuration class you wish to extend.
https://codeigniter4.github.io/CodeIgnit...registrars

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