Generic methods can participate in overloading alongside non-generic methods by using the 'overload' directive. If overload selection between a generic method and a non-generic method would otherwise be ambiguous, the compiler selects the non-generic method. 

For example:

type
  TFoo = class
    procedure Proc<T>(A: T);
    procedure Proc(A: String);
    procedure Test;
  end;

procedure TFoo.Test;
begin
  Proc('Hello'); // calls Proc(A: String);
  Proc<String>('Hello'); // calls Proc<T>(A: T);
end;

Two non-instantiated generics are considered assignment compatible only if they are identical or are aliases to a common type. 

Two instantiated generics are considered assignment compatible if the base types are identical (or are aliases to a common type) and the type arguments are identical.

Overview of Generics 

Terminology for Generics 

Declaring Generics 

Constraints in Generics 

Class Variable in Generics 

Changes in Standard Functions and Grammar