If A is a template for actual type, then why is typeof(A<,>) allowed?

Question

class Program
{
    static void Main(string[] args)
    {
        Type t = typeof(A<,>);
        Console.WriteLine(typeof(A<,>)); // prints A\'2[T1,T2]
          


        

Answer 1

Because A is an open generic, which the documentation explicitly says it supports.