Each format description document (known as an “fdd”) is assigned a six digit number starting with 000001 and a prefix of “fdd” (i.e., fdd000001 for WAVE Audio File Format). New fdds are assigned the next available number in a sequential list. On a practical level, we refer to the fdds by the last three digits of their identifier, for example fdd001 for WAVE.
Last modified 03 May 2022