June 3 — Some of the music industry’s parental-advisory labels about explicit content are about to get a bit more explicit themselves. Bertelsmann AG’s BMG record company, whose acts range from hip-hop duo OutKast to popular rock-jammers the Dave Matthews Band, Monday is set to announce plans to adopt a new system of detailed parental warnings. Acting voluntarily, BMG plans to place new advisory stickers on certain albums, specifying whether they have violent content, sexual content, strong language or some combination of the three, officials say. BMG plans to include the more-detailed warnings in advertising, including television, radio, print and...