U.S. design patents prepared for issue after June 30, 1996 and international design applications include a Locarno International Classification designation as part of the bibliographic data. The purpose of the international design classification designation is to enhance accessibility of design patents in foreign design search files as well as commercial databases.
The Locarno International Classification system was developed by members of the Paris Convention for the Protection of Industrial Property and is administered by the International Bureau of the World Intellectual Property Office (WIPO).
A Locarno International Classification designation consists of two pairs of numbers separated by a hyphen. The first pair of numbers designates a design class; the second pair of numbers indicates a particular subclass within the design class. The Locarno Classification manual, available from WIPO, delineates the individual classes and subclasses and includes: (1) a general list of classes of industrial designs divided into broad subclasses; and (2) an alphabetical list of specific industrial designs with an indication of the classes and subclasses into which they should be classified.
The Locarno designation included with design patent bibliographic data indicates the original classification of the patented design only. There is no provision for cross-reference designations within the Locarno system.
Locarno International Classifications are periodically revised by the Committee of Experts of the World Intellectual Property Organization.
The Image File Wrapper (IFW) issue classification form includes an area with the heading “International Classification”. A Locarno International Classification designation must be included on the issue slip when a design application is prepared for issue. The Locarno designation is printed on the design patent preceded by INID code  in compliance with ST.9 of the International Bureau. The abbreviation “LOC (7) CL.” follows INID code  and complies with the recommended abbreviation by the International Bureau.
An example Locarno designation as it appears on a U.S. Design Patent is as follows:
 LOC (7) CL. 02-02
The Office of Patent Classification has prepared a Concordance between the U.S. Design Classification classes and subclasses and the Locarno International Classification. In many areas of design subject matter, the U.S. Design Classification and Locarno Classification systems are parallel. In others, the two systems are conceptually different. For example, there is no specific provision within the Locarno system for designs which are simulative of other objects. The International Classification is generally based on the nature of the design rather than ornamental appearance. Accordingly, a one-to-one relationship between the two classification systems is not always possible.
Each suggested designation in the Concordance refers to a single Locarno International class and subclass. This designation, however, is not necessarily the only pertinent class and subclass in which the design could be properly classified since for some U.S. Design Classification designations, there is no direct parallel within the Locarno system.