Static classes in PHP via abstract keyword?

Question

According to the PHP manual, a class like this:

abstract class Example {}

cannot be instantiated. If I need a class without instance, e.g. for

Answer 1

abstract really is meant to indicate a "blueprint", as you call it, for class inheritance.

Registries generally follow a singleton pattern, which means they it would instantiate itself in a private variable. Defining it as abstract would prevent this from working.