Autodesk Developer Network members (see the topic Developer Support) have access to a debug version of the 3ds Max SDK and a special build of 3ds Max in that is compiled in debug mode.
This special version of 3ds Max has a purple animate button to distinguish it from the regular Release build of 3ds Max. There is also a Debug menu available on the toolbar. This menu provides options to review the 3ds Max command stack to see what is the current command mode and what modes have been previously pushed.
Also provided is a menu item 'Pipeline...' Each line in the dialog displayed by this command represents the state of the pipeline cache after a particular modifier or derived object. The following two letter codes identify the different channels.
An asterisk (*) following any of these channels indicates that the channel is "locked", meaning that is a shallow copy of a channel that is owned by a cache "upstream" in the pipeline.
The numbers following "t=" and "g=" are the memory addresses of the topology and geometry channel data, respectively, which are useful for debugging problems related to the shallow copying.