"Proclamation." Good word.
Perhaps my thought process is outdated or ill-informed, but I picture an announcement from a US president or other government official, and a proclamation from a throne or through a throne speech. Looking at the definition I can see that I am wrong in this mental imagery above.
A proclamation is a formal, public, and often official announcement or declaration, usually issued by a high-ranking authority, such as a head of state or mayor, to declare something of significance. It serves to announce new laws, recognize events, or declare public holidays, often being non-binding.