Yes - there is a binary collation.
w.r.t. arbitrary:
The ordering must be deterministic so that indexes can maintain sorted order. It's possible to create a custom collation to have your own ordering - but I would say most users don't do that.
w.r.t. arbitrary:
The ordering must be deterministic so that indexes can maintain sorted order. It's possible to create a custom collation to have your own ordering - but I would say most users don't do that.