An even more detailed explanation of SuDoc classification is available here from the University of Denver. That is, the documents are arranged by the agency which produced them rather than by the subject they cover. Below is a table with some examples of the agencies and their classes. If you compare these to the classes in Library of Congress classification, you can see there is no commonality. The reference desk is located on the main floor in the reference area.
Reference librarians are on duty at the reference desk nearly all the time the library is open.
When you have questions about library research, ask a reference librarian at the reference desk. Student workers at the circulation desk are trained to check out and reshelve books and reserve materials and cannot answer your questions about how to use the library. Ask the Librarian The reference librarian will teach you how to use the library and its resources and help you find the information you want. The librarians in the Academic Library, like all librarians, are dedicated to the work of organizing, storing, and retrieving information. The librarian will not write your paper for you but will help you find the information you need to write your own paper.