Just to clarify, Hallq uses “mutual knowledge” as if it’s synonymous to “common knowledge”, but game theorists use the two terms as a contrast: mutual knowledge of A is when everyone knows A, common knowledge of A is when everyone knows that everyone knows that everyone knows (...) A. So this is about raising to common knowledge things that were merely mutual knowledge.
Just to clarify, Hallq uses “mutual knowledge” as if it’s synonymous to “common knowledge”, but game theorists use the two terms as a contrast: mutual knowledge of A is when everyone knows A, common knowledge of A is when everyone knows that everyone knows that everyone knows (...) A. So this is about raising to common knowledge things that were merely mutual knowledge.