MANILA- President Rodrigo Duterte praised Tuesday the close-knit ties that bind graduates of the Philippine Military Academy as he hailed the military school's "mistah" culture.

"Mistah" is military slang for "batchmate" among graduates of the PMA- a word that entails a deep sense of camaraderie that they carry throughout life.

"There is much mystique hidden in that word. It is more than friendship. It is more than camaraderie. It is a feeling and a sense of pride that only a PMA graduate can fully comprehend and appreciate," the President said when he read his prepared speech before PMA alumni in Pasay City.

"It is said that to be called Mistah is the highest compliment that can ever be extended to a PMAer by his peers," he added.

Among those present in the audience were PMA alumni Defense Chief Delfin Lorenzana, Sen. Ronald "Bato" Dela Rosa, Armed Forces of the Philippines Chief of Staff Felimon Santos Jr., and Philippine National Police Chief Archie Gamboa.

For PMA alumni, Duterte said mistah is a sacred word while for outsiders, the word represents values ideal of a soldier.

"Its sanctity cannot be challenged," he said.

The President urged graduates of the top military school to police its own ranks as he warned them that the prestige tied to the academy is only as good as the graduates' reputation.

"One scalawag among you can destroy or dent the image and reputation of every PMAer, your Alma Mater and your association included," he said.

"It takes only one fly to spoil a feast. It takes only one scandal to ruin your avowed moral and ethical standards," he added.

Reports of abuse are fairly common in the PMA, which figured in a controversy last September over the hazing death of one of its plebes.

The incident prompted the resignation of Lt. Gen. Ronnie Evangelista as head of the top military school.

• At the PMA, a thin line between instilling discipline and inflicting abuse

Several of its graduates have also been tagged in wrongdoing, including former police chief Oscar Albayalde of the PMA Sinagtala Class of 1986, who was recently indicted for allegedly protecting police officers linked to the sale of seized drugs in 2013.

He has denied the allegations.

• DOJ indicts Albayalde, 12 'ninja' cops for graft over 2013 Pampanga drug raid