- Professional license. In the United States, a designation earned by a person from a state agency that allows this person to exercise some occupation. Professional licenses usually require the university title for that profession.
- Trade certificate (also known as professional certificate, professional designation, or, simply, certification). A designation earned by a person from a professional society, certification body, or, possibly, from a private certifier to assure qualification to perform a job or task. Some trade certificates must be renewed periodically, or may be valid for a specific period of time (e.g., the lifetime of the product upon which the individual is certified).
- Work experience. Any experience that a person gains while working in a specific field or occupation, but the expression is widely used to mean a type of volunteer work that is commonly intended for young people, often students, to get a feel for professional working environments.
- Work sample test (also work test or work simulation). A sample of behavior that can be used to predict future performance in similar work situations. Its result is an employment credential that provides information relating to skills that may be difficult to assess in other ways.
- Professional award. A prize or other mark of recognition given in honor of an achievement in a specific profession.
- Profession-related performance. Any performance related in a specific profession. Examples of such performances may include delivering a lecture, serving on a board, publishing a book, writing an article, especially reviewed by peers or made in well-known settings and/or verified by a reputable source.
- Professional recommendation. A suggestion or proposal to hire somebody because of his or her professional capacity. Usually, professional recommendations include testimonies of the recommended person's achievements. Letter of recommendation refers to not only professional recommendations.
- Client feedback such as clients letters or emails
- Professional association membership. Membership in a professional association.