A question from America

Glen of Imaal Terrier standard says”Coat– Medium length, of harsh texture with a soft undercoat. The coat may be tidied to present a neat outline characteristic of a rough-and-ready working terrier. Over-trimming of dogs is undesirable.” What do folks think medium length is? There was talk on another site that medium is 1.5 inches. Please state your opinion, no personal comments on anyone’s breeding, dogs, or children