Occupations Generally Requiring a High School Diploma At entry level, these occupations usually can be filled by persons with a high school diploma, with some on-the-job training. However, employers may give preference to those with some formal postsecondary training or work experience. Cashiers General office clerks Interviewing clerks Receptionists and information clerks Salespersons, retail Sales representatives, except retail Secretaries, except legal and medical Stock clerks, sales floor Traffic/shipping/receiving clerks Travel agents