What is the legal purpose of “marking” in patent law?

The legal purpose of "marking" in patent law is primarily to indicate that a product is patented and to inform the public about the existence of the patent. When a product is marked with the relevant patent number, it serves as a notice to potential infringers that the product is protected by patent rights, thereby fulfilling a key role in the promotion and enforcement of patent rights. This marking not only helps to prevent unintentional infringement by informing the public but also can play a significant role in establishing damages if infringement does occur. By ensuring public awareness of patented inventions, marking contributes to the careful navigation of patent rights and responsibilities within the marketplace.

Additionally, while marking can assist in marketing and sales, that is not its primary legal purpose. The indefinite exclusivity of patent rights does not stem from marking; instead, it is dictated by the terms of the patent grant itself. Furthermore, marking does not have a direct impact on the patent application review process, which follows its own established procedures.