SECURITY CODING

A method of security coding an article which comprises applying to the article an identification mark comprising at least one colorless or weakly-colored infra-red absorbing material and an article carrying one or more identification codes applied according to the method. The method is suitable for marking documents, currency and equivalents, such as cheques, credit cards and tickets, and for the identification of copyright materials and high valued added goods, such as tapes, cassettes, books, films, cameras, perfumes, spirits and designer goods to inhibit counterfeiting.