I was reading the 3.0 documentation:
http://docs.python.org/dev/3.0/library/string.html#formatstrings which
indicated that an identifier was required.  I was unaware of the
implementation note in the PEP.

They only issue remaining is that for the example in the title of this
issue, "{ +(}".format(**{' +(': 44}), no error is generated.  I agree
that this is a nit and presumably the will of the community reviewing
the PEP, so agree to having the issue rejected.

I would reject it myself, but am unable to do so...

Thank you for pointing out the PEP to me.