The ASA is an organization that regulates advertising in the UK. It investigates complaints about ads, sales promotions, and direct marketing to determine if they violate codes stipulating that all claims must be substantiated with evidence and marketing cannot mislead through inaccuracy, ambiguity, exaggeration or omission.

1. ASA
The ASA stands for advertising standards authority it’s an organization of
advertising in the UK. The ASA deal with advertisements, sales promotions
and direct marketing in the UK by investigating complaints made about; ads,
sales promotions or direct marketing.
These codes stipulate that "before distributing or submitting a marketing
communication for publication, marketers must hold documentary evidence to
prove all claims, whether direct or implied, that are capable of objective
substantiation” and that "no marketing communication should mislead, or be
likely to mislead, by inaccuracy, ambiguity, exaggeration, omission or
otherwise.