University of Kentucky distinguishes between three types of postdoctoral appointments as per Administrative Regulation 5:1
A. Postdoctoral Scholar. “Postdoctoral Scholar” means an individual who has an earned doctoral degree and is pursuing an individualized program of advanced training in research, in teaching or other aspects of academic work, or any combination of these activities. Although participation in the program provides advanced training, an academic assignment is required as a condition of appointment with salary. A Postdoctoral Scholar is both a temporary academic staff employee and a postdoctoral student.
B. Postdoctoral Fellow. “Postdoctoral Fellow” means an individual who has an earned doctoral degree and is a recipient of a fellowship or training award. Through such an award, a Postdoctoral Fellow receives a stipend or living allowance (neither of which are considered salary) from grant funds provided specifically for a particular field of study or training. No academic assignment is required as a condition of receiving the stipend. A Postdoctoral Fellow is a postdoctoral student but not an employee.
C. Visiting Scholar. “Visiting Scholar” means an individual who is pursuing an independent program of research at the University, or is participating in an existing research program, ordinarily while on leave from another professional position. Because of a Visiting Scholar’s advanced training and experience beyond that of an apprentice or learner, they are excluded from designation as a Postdoctoral Scholar or Fellow. A Visiting Scholar need not have a doctoral degree, but must have significant scholarly experience. A Visiting Scholar is temporary academic staff. Appointments as Visiting Scholars are normally without salary from the University.
See AR5:1 for information on eligibility, benefits, and other information.