Actually, there is another procedure which could be followed when you
don't have the ability to negotiate (as a news poster does not have with
a receiving mail client.)
a) Declare that all new tools be able to accept the new format, both
USENET and MAIL. Make it clear that if a tool decodes neither the 7
bit and 8 bit formats, it must not simply implement the 7 bit because
that is coming first, it must handle both.
b) At first, however, do not generate the new format. Generate the
backwards compatible format (7 bit)
c) As a sector of the net (USENET) moves to being able to declare
use of the new format (8 bit) possible because at this point all clients
are required to handle it, it can do so. All gateways must also be able
to map to the older format if passing material to it.
d) Eventually all tools handle the new format. Use of the backwards
compatible format can be deprecated.
e) At some point tools that generate the 7 bit format are all but gone.
Use of it can be forbidden, and support for it no longer required.