Undocumented commands & features are not guaranteed or supported by ANSYS or the ASDs (they also do not have error reports associated with them), but they are sometimes quite useful. Please use at your own risk. Undocumented commands are collected from ASD websites, ANSYS, Inc., and XANSYS mailing List (esp. John Crawford and John Swanson's contributions), and the author's own findings.
Some of these commands are present in later versions of ANSYS (e.g., ANSYS 5.6, 5.7). Others are "old" legacy commands which became undocumented in subsequent versions of ANSYS. Additional reasons why commands are undocumented: (a) The feature is either untested or insufficiently tested due to time constraints, (b) The feature has been tested but did not pass sufficiently to warrant release, (c) KEYOPTs, program options, etc. that are requested by specific users but are not deemed useful to the general user community are sometimes included without general release, (d) Features that are "unsupportable" and minimally tested, (e) Options risky to the user (CNVR,,,,,,,-1 for example), (f) Partially completed items that are still "buggy" but of use in a limited sense for experimental Beta testing by select customers. [Taken from ANSYS, Inc.]
Notes are added to indicate revisions which were verified by the author or others, but this does not necessarily mean that the command is only applicable to a particular revision unless stated as such.