Policy/Rule Question

Re: Conversations in the for sale section.

Can someone explicitly define what is considered a conversation in the for sale section? Does it include any and all replies to the seller? Thnx
From what I gather, you can only ask questions about the product for sale to the seller. All offers and exchange of info must be done through a PM. No casual comments like "the piece is awesome, dude!" or "you can buy that new from Summit cheaper" .... Exceptions seem to be if someone ask something like "is that a 1965?" and the seller says "i don't know", then somebody can say "it is not a '65".