The veterans preference law of 1944 requires that five points be added to the entry-level civil service examination scores of any veterans who served in either world war, in Korea, or who served more than 100 consecutive days on active service between 1955 and October 1976. (Those in the all-volunteer Army are not covered.)

After a veteran gets a federal job, he can re-use the extra exam points whenever he competes for another federal post. (They cannot, however, be used to get promotions within an agency when those civil service hiring lists are not used.)

Ten points are added to the scores of disabled veterans, their spouses and mothers, and in some cases the spouses and mothers of deceased veterans if the spouses and mothers apply for federal jobs. (Disability can range from very nominal injuries to total paralysis, according to a Defense Department spokesman.)

An employer cannot pass over a veteran job applicant if his test scores and other qualifications are equal to other applicants, unless the Civil Service Commission grants the employing agency a waiver.

Veterans also get preference over other job holders when their agency decides to lay people off. (Retired military personnel, i.e., those collecting military pension, do not have this protection, though their military service is counted toward seniority.)

Carter's proposed changes as he outlines them, would not affect the life-time preferences given to disabled veterans.

In fact, his plan would increase employment assistance for the severely disabled and also would strengthen and expand training and hiring advantages provided for Vietnam veterans under the Veterans Readjustment Authority.

For nondisabled veterans, begnning in 1980 the president's original plan would put a 10-year limit on special advantages in hiring and job retention.

Job retention advantages would be limited to three years for both enlisted men and officers below major who retired from the service after 20 years (with five years credit for military service added to their seniority after that).

For high-ranking military retirees (major or higher) there would be no special preferences in getting or holding a job.

Administration officials have said they will accept a compromise which instead of a ten-year limit provide for a 15-year limit on the hiring preferences, or a one-time successful use of them to get a job, whichever come first. The compromise would also expand the scope of special hiring advantages for the severely disabled to include those with less serious disablilites; and would extend to eight years the three-year limit on security against layoffs.

If the president's original proposals were to be enacted, the number of those eligible for five-point veterans preference by late 1981 would drop from 27.4 million to about three million, officials say. There would also remain the 2.2 million 10-point (disabled) veterans whose rights would not be diminished by the changes.