Library of Congress

Preassigned Control Number Program

The Library of Congress > Preassigned Control Number Program > About PCN

The purpose of the Preassigned Control Number (PCN) program is to enable the Library of Congress to assign control numbers in advance of publication to those titles that may be added to the Library's collections. The publisher prints the control number in the book and thereby facilitates cataloging and other book processing activities. The PCN links the book to any record which the Library of Congress, other libraries, bibliographic utilities, or book vendors may create.