Many of the government's 120,000 engineers, scientists, medical personnel and clerical employes who are already paid above-scale rates could be in line for another increase this year, plus back pay for six years, pending the outcome of a court battle between Uncle Sam and the National Treasury Employees Union.

Under current government policy, special-rate employes in hard-to-fill jobs are paid anywhere from 3 percent to 30 percent more than regular civil servants in the same grades. In the early 1980s the government stopped giving those special-rate employes the regular general civil service pay increase, on the ground that they already were paid above regular rates.

Last March the U.S. District Court for the District of Columbia ordered the government to include those special-rate employes in general pay increases and to give some workers back pay retroactive to 1982, based on a lawsuit brought by the union.

The government has appealed the ruling.

In April the Office of Personnel Management added 32,000 Washington area clerical employes to the special-rate category, giving them raises ranging from 3 percent to 23 percent.

For most clerical workers the adjustment averaged 4 percent. But OPM, as reported here yesterday, has said that none of the special-rate employes who got raises last year will be included in the 2 percent increase that goes into effect this month for other white-collar civilians.

If the government loses the case now on appeal, it could mean raises -- and substantial back pay -- for thousands of special-raters.Meetings

Darcia Bracker of Commerce's National Technical Information Service will speak at the Training Officers Conference luncheon Tuesday at the Fort McNair Officers Club. Call 566-9659.

Clarence Thomas, chairman of the Equal Employment Opportunity Commission, will speak at the Jan. 14 luncheon of the Society of Federal Labor Relations Professionals. The meeting is at the George Washington University Club. Call 696-5880.

The Jan. 14 meeting of the Federal Executive Institute Alumni Association will honor James Colvard, who recently retired as deputy director of the Office of Personnel Management. Ambassador Bruce Laingen, executive director of the National Commission on Public Service, will speak at the luncheon at Fort McNair's officers club. Call 639-6012.

Air Force civilian staff members who worked in civilian personnel programs are planning a reunion May 27-28 in Arlington. For details call Jim Abernathy at 323-1770.

Federal office-space planners are invited to the annual quality workplace session Jan. 20-21 at the Washington Convention Center. Firms will display the latest in everything, from word processors to air-purifying systems. For information call Linda Roth at 289-4687. Is Government Working?

The mailroom at Government Executive magazine may have to go into overtime to handle results of a reader opinion poll in this month's issue. The postage-paid ballot questionnaire asks readers their opinions on everything from federal pay and the public image of federal workers to voting patterns.