What is the Locarno Classification system for design patents?

This page is an FAQ based on guidance from the Manual of Patent Examining Procedure. It is provided as guidance, with links to the ground truth sources. This is information only: it is not legal advice.

The Locarno Classification system is an international classification system for industrial designs. It’s used to enhance accessibility of design patents in foreign search files and commercial databases. According to the MPEP, 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 Classification designation consists of two pairs of numbers separated by a hyphen, where the first pair designates a design class, and the second pair indicates a particular subclass within that design class.