An industry-wide standard on the copy controls for digital entertainment is needed to aid consumers, the trade body for 7,000 US music stores has said.
If a compatible system cannot be created, an alternative method must be adopted, the National Association of Recording Merchandisers (Narm) added.
There are currently several different technologies which limit how CDs, DVDs and downloads can be transferred.
Record and film companies argue digital locks help to prevent illegal copying.
