Victoria 2 Wiki
This article is considered accurate for the current version of the game.
Found the BBC is a decision unique to United Kingdom.
It shows up in the decision tab in the year 1900 and has only one requirement: United Kingdom needs to have invented National Radio Networks, which is under Psychology (Culture technology).
It changes the relation with every single independent country by 5, removes 0.5 militancy and gives 10 Prestige.