Librarians at UNC Chapel are classed as EPA Non Faculty (Exempt from the Personnel Act) - this is the same classification as all higher administrative posts e.g. provosts the structure is here:
<http://www.lib.unc.edu/personnel/Structure.pdf>
reappointment timelines here:
<http://www.lib.unc.edu/personnel/Asst-Assoc-Lib%20Timeline.jpg>
ranking structure here:
<http://www.lib.unc.edu/personnel/rank_chart.pdf>