Section 108 authorizes libraries to make copies requested by patrons. The law is neutral regarding the medium of reproduction, thus, "copies" are not so narrowly defined as they are in the archive provisions.
Articles or small parts of works
If a patron requests part of a book or an article the library has in its collection (1), the library can make the copy so long as it complies with the provisions of Section 108 (d):
Whole works
If a patron requests a copy of an entire work, the library can make the copy so long as it complies with the provisions of Section 108 (e):
Warning of copyright
Sections 108 (d)(2) and (e)(2) require that libraries warn patrons about copyright law, and the Copyright Office tells us exactly what the warning should say (2). The regulation requires that we inform the patron about certain facts (see below), but it does not require us to be sure that a patron is acting properly in making a request or require that they declare compliance with the law. The library is, however, permitted to deny requests that it believes would violate the law.
Footnotes:
1 See making copies: interlibrary loan for guidance regarding requests that cannot be fulfilled from the library's collection and for requests from other libraries for their patrons.
2 37 CFR Section 201.14. The warning can be found on pages 19 and 20 of Copyright Office Circular 21, "Reproduction of Copyrighted Works by Educators and Librarians." To find the warning quickly, search the document for 201.14.