Overview#Data Country Codes (DCC) are the ITU-T Country Codes which as far as we can tell is the same as the ISO 3166-1 alpha-2
According to Rec. ITU-T X.660 | ISO/IEC 9834-1, clause A.2.5, subsequent arcs have the values of Data Country Codes (DCC) as defined in Rec. ITU-T X.121. Arcs below this are determined as necessary by the Administration of the country identified by the DCC.
See the list of Data Country or Geographical Area Codes (sub-arcs in this OID repository are in accordance with the list of DCC codes issued on 15 Mar 2011).