One example of an active effort to prevent the genericization of a trademark was that of the Lego Company, which printed in manuals in the 1970s and 1980s a request to customers that they call the company's interlocking plastic building blocks "'Lego bricks', 'blocks' or 'toys', and not 'Legos'." While this went largely unheeded, and many children and adults in the U.S. referred to and continue to refer to the pieces as "Legos", use of the deprecated term remained largely confined to the Lego Company's own products – and not, for example, to Tyco's competing and interchangeable product – so genericization of the Lego trademark did not occur.