Defines how an NFC-enabled device in Reader/Writer Mode detects, reads and writes a NDEF Message on a NFC Forum Type 4 Tag. The communication with this Forum Tag type is based on the ISO Data Exchange Protocol (ISO-DEP) which is fully compatible with the ISO/IEC 14443 standard series. This protocol is either based on NFC-A or NFC-B Technology.

Version 1.1 of the Type 4 Tag Specification includes updates to support time-optimized implementations to improve the performance for reading NFC Forum tags in support of the new TNEP protocol.

Version 1.2 of the Type 4 Tag technical specification reflects the removal of NFC Forum Type 1 Tag features from Technical Specification Release 2021 to simplify the implementation of future NFC enabled devices without reducing the user experience. The NDEF read procedure was also improved to update the length information if not directly preceded by an NDEF detection procedure.