The City of Cambridge received a nationally recognized award last week for its efforts to curb underage drinking.

A nonprofit group known as the National Association of State Alcohol and Drug Abuse Directors (NASADAD) awarded its 2007 National Exemplary Award for Innovative Substance Abuse Programs to the city for a program that trains local alcohol servers and sellers to prevent underage drinking.

The initiative, called “21 Proof,” is unique in “the collaboration between the licensees and the license commission,” according to Frank W. Connelly, trainer and community organizer of the Cambridge Prevention Coalition (CPC), one of the three organizations that oversees 21 Proof.

21 Proof, Connelly added, educates not only managers and servers, but also retailers and wholesalers in identifying behavioral cues of intoxication and developing intervention strategies.

Alan Moghul, director of prevention at NASADAD, said that the award program—established a little over 20 years ago—“seeks to identify and award very innovative, very successful, cutting-edge programs that aim to prevent substance abuse in their community.”

21 Proof’s unique strategy set them apart from the pool of 40 applicants, Moghul said.

“They are very effective, and this type of environmental strategy takes into account all the interests of stakeholders, business community, retailers, wholesalers, as well as law enforcement, community leaders, parents, and local schools,” he said.

Harvard Square participants include Border Cafe and the Hong Kong Restaurant.

“This is a real honor—one of the highest in substance abuse prevention,” Gisela Rots, director of the CPC, said in a statement released last week.

“21 Proof is familiar with the people, the places, and the unique culture within Cambridge and its institutions,” said Ryan M. Travia, director of the Office of Alcohol and Other Drug Services at University Health Services.

In addition to the CPC, 21 Proof is a joint venture with the Cambridge License Commission and the Cambridge License Advisory Board.