More than 40 media groups in Mexico have agreed on common guidelines on how to cover the drug wars there.
The newspapers and broadcasters have agreed not to glorify drug traffickers or publish cartel propaganda.
They also promised joint action to protect journalists, at least 20 of whom have been killed since 2006.
The accord defends the media's right to criticise Mexican government policy and actions in the conflict.
The agreement was signed at a ceremony in Mexico City. The participants own over 700 television networks, radio stations and newspapers.
Among them were the top broadcasters, Televisa and TV Azteca.
However, some leading newspapers - including Reforma, La Jornada and Proceso - did not sign up.
President Felipe Calderon has welcomed the agreement.