On Thu, Jul 02, 2015 at 11:57:51AM +0100,
Colin Perkins <csp(_at_)csperkins(_dot_)org> wrote
a message of 22 lines which said:
At negligible cost.
How much? I don't remember having seen the actual cost mentioned
anywhere. And, as John Klensin noticed here, the agreement between the
RFC editor and the FIFA of DOI is secret.