The term applied to asymmetric digital subscriber line version 2 (ADSL2) while it was under development. The term G.dmt.bis derives from the fact that ADSL is specified in the ITU-T G Series Recommendations as G.992.3 and G.992.4, employs discrete multitone (DMT) modulation, and is the second (bis) version. See also ADSL, DMT, G Series, ITU-T, and modulation.