Animation tracks can be locked to prevent editing of animatable parameters. One example where locking animatable parameters and animation tracks would be useful is when the rigger creates a character and hands it off to animators for animation. The rigger could lock all parameters that he doesn't want the animators to edit, such as bone parameters (e.g. position, rotation, scale, etc.), and leave unlocked those that are meant to be used for animation.

Plug-ins that define and store their parameters as IParamBlock2 don't have to do anything in order to support lockable tracks. Controller plug-ins should consider supporting the ILockedTrack interface in order to support locking and unlocking of their animatable parameters.

For more information on what a controller plug-in should do to support being lock-able, please see maxsdk\include\ILockedTracks.h (note the detailed description at the bottom of the file), and the controllers that ship as SDK samples (maxsdk\samples\controllers).