This work proposes a definition of Information and Communication Technologies (ICT) based on the technology classes of the International Patent Classification (IPC) in which patents are classified. This new taxonomy, called the “J tag”, aligns with the definitions of the ICT sector (2007) and of ICT products (2008) put forward by the OECD, and stems from the in-depth knowledge of Japan Patent Office experts, as well of experts from the Intellectual Property (IP) Offices participating in the OECD-led IP Task Force. Expert judgment of patent class content, relevance for ICT-related products, completeness and accuracy are the principles guiding the inclusion of IPC classes in the “J tag” taxonomy. ICT technologies are subdivided into 13 areas defined with respect to the specific technical features and functions they are supposed to accomplish (e.g. mobile communication), and details provided about the ways in which technologies relate to ICT products.