So we have always played with the discard pile faceup, so anyone who wish can read the most recenly played action card, but recently had a bit of a quarrel about the secret objective "Form a spy network" so I have a few questions for clarification. Which is also applicable when you have to discard more than 1 action card at the same time.

First if all is the discard pile supposed to be faceup or facedown?

Second when a person discards more than 1 action card, are other players allowed to read the discarded cards other than the top card`? Assuming the discard pile is faceup.

We play that discard pile is face up and can be inspected at any time. Hold over from 3rd. Unsure if it correct.

As far as I can remember, any face up pile is completely open knowledge and can be looked through at any time on your turn. It may be a hold over from some other game, but that is how our group has always played.

Never even occurred to me that a player wouldn’t be able to look through a discard pile.

What does the spy network card say that calls it into question?