It was Friday night, but they wore their Sunday best. There were small boys in stiff blue suits and young girls with freshly curled hair. Their exuberant elders, just as nattily attired, filled the church foyer, pumping hands and slapping backs, pinning corsages and smoothing white gloves.

Voices rose in nervous excitement in the rush to exchange greetings and last-minute instructions. One young woman ducked her head bashfully, then grinned up at her friend: "I'm graduating tonight."

She and 177 others were about to receive diplomas from the School of Ushering, in a ceremony sponsored by the Interdenominational Church Ushers Association of D.C. Inc.

The graduating class came from 78 local black churches, mostly Baptist, and its members would leave that night ready to return to their congregations, said valedictorian Joyce Hall, "equipped with a professional touch of class."

The graduates, ranging in age from 10 to 72, were dressed in official uniformity: the men and boys in formal dark suits, the women in crisp white, the girls in navy and white. They had mastered the "universal" style of ushering taught by the school since 1948: an elaborate system of silent codes and precise maneuvers.

If the technique on display for more than 500 guests at the First Baptist Church of Highland Park in Landover had an almost military flair, the ceremony itself was more of a revival, complete with preaching and gospel singing.

"God was the first usher, Abraham was the second usher, and Moses was the third," boomed the Rev. R. Clinton Washington, pastor of the Jerusalem Baptist Church in Northwest Washington, and the crowd roared its agreement during last week's ceremonies.

The theme sounded throughout the evening stressed the importance of the ushers' role within the church. As one page of the program read: "It is certain that almost everyone that comes to church . . . will come in direct contact with the ushers first," making a proper welcome essential.

According to Nettie Martin, the association's president and herself an usher since 1936, the post requires friendliness, tact, and alertness to the possibility of emergencies.

Martin still remembers, more than a quarter of a century later, a crisis at her church, Rock Creek Baptist in Northwest Washington.

"We had to use the distress signal" when a heater set a curtain in the choir loft on fire, she recalled. And the signal? "Bringing both hands back across your head" as if "brushing your hair back." This informed church officials and other ushers, without alarming the congregation, and the fire was put out without incident, Martin said.

Last week's graduates learned that code as well as the signals for getting additional fans or programs, how to stand and how to extend courtesies and other services, during eight months of classes held once every week from last October through June at River Terrace Elementary School in Northeast Washington. "Juniors," aged 8 to 13, pay $7 for the series of lectures, films, demonstrations and drills; the charge for adults is $12.

The ICUA chapter school is affiliated with the United Church Ushers Association of America, a Denver-based national organization. Churches throughout the country use the same techniques.

"I didn't know there was that much to learn in ushering," said District resident Tawana Wicker, a graduate who found the "formal procedures" slightly different from the style of ushering prevalent at her church, Metropolitan AME. For practice, Wicker also ushers at several other churches that follow the national formula in Sunday services.

Some graduates will serve in churches that already use this method and others will pioneer the technique in their churches, teaching would-be ushers the fine points.

Thirteen-year-old Surry Young, one of the juniors, described two of those points: Ushers "greet everybody," and they're "not supposed to chew gum," he said.

Forty of this year's class took postgraduate work, learning, among other things, methods for taking up collections. Five also trained to be instructors.

But their education does not necessarily stop there, according to Herman Jones, a former usher who is a deacon of the church where the ceremony was held. "A lot of people go from ushers to ministers, right on up the ladder," he said.