The Nice Classification for trademarks goods and services has been in effect since 1961 and is now updated annually. A new edition is published every five years, and each edition is revised annually. The 2021 version of the current 11th Edition is effective from January 1, 2021.
We have updated the listing in the TMCloud Practice Guide and in the Goods and Services section on the main Trademark page, and have added some useful links.
You can review the new text of the Class Headings and Explanatory Notes here:
Use of the Nice Classification is mandatory in the 88 countries party to the Nice Agreement and in practice the classification system is used everywhere even if the latest version has not been formally adopted.