  Dynamic epistemic logics which model abilities of agents to make various
announcements and influence each other's knowledge have been studied
extensively in recent years. Two notable examples of such logics are Group
Announcement Logic and Coalition Announcement Logic. They allow us to reason
about what groups of agents can achieve through joint announcements in
non-competitive and competitive environments. In this paper, we consider a
combination of these logics -- Coalition and Relativised Group Announcement
Logic and provide its complete axiomatisation. Moreover, we partially answer
the question of how group and coalition announcement operators interact, and
settle some other open problems.
