In an effort to better communicate internal policies on classification, WIPO has published its Examination Guidelines Concerning the Classification of Goods and Services in International Applications. The document serves as a guide to the goods and services examination principles applied by WIPO's trademark examiners.

The Guidelines are structured in three sections containing (i) some general information on the Madrid System and the Nice Classification, (ii) information on the classification principles applied by WIPO, as well as (iii) practical information and formatting guidelines. 

The Guidelines, which are available in English, French and Spanish, can be found here.