Amendment 1 to Recommendation ITU-T G.9903 (2012) contains:The support for an optional coherent mode for use in CENELEC bandplans;Support for a new bandplan in CENELEC B;A Regional Annex for Japan (Annex K);A new routing algorithm (LOADng) that replaces the old one (LOAD);A clause on coexistence with other NB-PLC technologies;Various clarifications and corrections including CFA, Header Compression, and channel access mechanism;A major editorial restructuring.