Explicit self-references with no type / difference with ''this''

Question

I understand the use for explicitly typed self-references:

trait T {
  self : T2 =>
  ...
}

In the body, self is an alias f

Answer 1

In that case self is a another way of saying this.

If you happen to have an inner class, however, this inside the inner class would be the inner class, and self would be the container class.

That's the only difference AFAIK