This revision to Annex A/P.862 describes the revised ANSI C reference implementation of PESQ, which includes modes of operation for Recommendation P.862.1 (narrowband MOS-LQO mapping) and Recommendation P.862.2 (the wideband extension). It also describes the conformance testing procedures for P.862 and P.862.2. This revision replaces Annex A to P.862 (February 2001) and Amendment 1 to P.862 (March 2003).