ASA here is the Advertising Standards Authority, a British body that watches over advertising in the UK. If someone thinks an advertisement is untrue, nasty, or offensive, they can complain to the ASA. The ASA can tell a company to change the ad or stop using it. It is not the police, and it is not a world organisation — it is a UK advertising watchdog. Newspapers in Britain say “the ASA” the way you might name a referee. Though actually many other groups use the same three letters (standards bodies, film-speed codes, and so on), so this meaning is the British ads one, not every ASA you will ever see.