al sign emitter or recipient.

*  The medium tends to be common between emitter and recipient (sound
waves, magazine page, billboard, etc., with more variation possible in the
instance of computer networks).

*  There is complexity within each of these aspects, but most especially
with respect to purposes and understandings.

* Correspondence among understandings has a lot to do with correspondence
(or symmetry) among purposes.

*  The general purpose for efforts like SUO, in my opinion, has to do
specifica