In addition to the basic signature instructions in 1.1 above, users of NN
need to edit their ~/.nn/init file so that it contains the following:

set query-signature off
set append-signature-mail on
set append-signature-post off

Note that the reason that you need to `set append-signature-post off' is
that the news posting software (usually inews) automatically appends
 ~/.signature if it exists.  If you `set append-signature-post on' then
both nn and inews append your sig and you'll send out two identical sigs
every time.