You can encode it, but it is not enforced. For instance, I can refer to every instance/argument when I use a Person object as `person` or whatever name of the c

You can encode it, but it is not enforced. For instance, I can refer to every instance/argument when I use a Person object as `person` or whatever name of the class is, but when you have many developers working on a large system, these things tend to slowly spiral unless you establish strict guidelines early on and enforce through code reviews. Or you can use types where it's enforced by the compiler.