This Corrigendum 2 contains corrections to the fifth edition (06/2016) of ITU-T Recommendation G.709/Y.1331, related to the: -Terms defined elsewhere (3.1). -B100G MOTUm interface principal information containment relationships (6.2). -Maximum number of ODTUCn.1 and ODTUCn.ts instances that can be multiplexed into an ODTUGCn in Figure 7-1 (7.1). -Multiplexing of ODUk into OPUCn specification (7.4). -Update of FlexE terminology (3.1.6, 12.2.6, Appendix XIV). -Missing of a payload type code point value for 50GBASE-R mapping into ODUflex (15.9.2.1.1). -Atomic function that is processing PMI overhead (16). -50GBASE-R mapping into OPUflex (17.13.3). -Mapping ODU1 into ODTU12 (19.5.1). -Cm,max and Cn,max equations 19-7, 19-13, 20-7 and 20-13 (19.6, 20.5). -Non-applicability of specifications in Annexes E.4 and F.3 to 100GBASE-R (E.4, E.4.1, E.4.2, E.4.3, F.3.2.1, F.3.3). -Non-applicability of Ethernet LF insertion specification in G.709 (E.4.2). -OTUCn sub rates (OTUCn-M) Applications (Appendix XIII).