ISO/IEC 14443

ISO/IEC 14443 is the foundational international standard for proximity contactless smart cards operating at 13.56 MHz. It defines the complete communication stack in four parts: physical characteristics (Part 1), RF interface (Part 2), initialization and anti-collision for Type A and Type B (Part 3), and transmission protocol (Part 4). Nearly all NFC tags, payment cards, and identity documents comply with this standard.