It feels a bit as of this forum is very much for minutiae so forgive me asking obvious questions again.
It appears, reading some posts on other topics, that it is legitimate, following a declaration of a charge by unit A on B, for B to declare that it too is charging, at A.  Is that the case? Can't see anything stating otherwise. If so, and you can always declare a reciprocal charge, what's the function for which people use the countercharge mechanic? (I think we understand intercept – puts you in the way of the charging unit to shield the intended target.)
On a related topic, if a charging TuG has a path of charge which contacts a different unit which is a SuG, not the target of the charge, what happens? Does that unit have the normal runaway/skirmish options? Technically, it has been contacted by a charging unit and could therefore be destroyed?

Thanks, all clear.

Literally started playing these rules yesterday and my friend has borrowed the rulebook.  As usual there are things bothering me the day after a game when I am supposed to be working.  Please indulge me if you have a few seconds:  There is a charge section to the turn, all very clear, but we couldn't find a note specifically forbidding using a prompted move action, not a charge, to contact an enemy. In which case there would then be a (non-charge) combat in the following phase.  Is this permissible? It wouldn't be in most other rules I know. I guess two formations could trudge into contact and start chopping away at each other, in real life.   Did we just miss the note? I haven't picked my username for nothing....