Looked in knowledgebase, couldn't find anything.
 
Anyone knows what it does and the "desirable" value for this is? Mine is at -2.  Value seems to go from -2 to 2.

That value isn't used anymore so don't bother setting it. 
It was superseded by MMCSS task names which is a more powerful way to configure MMCSS. There is more info on task name configuration in the help here. The actual details about task configuration are pretty low level and can be found here.

Noel Borthwick [Cakewalk]
That value isn't used anymore so don't bother setting it. 
It was superseded by MMCSS task names which is a more powerful way to configure MMCSS. There is more info on task name configuration in the help here. The actual details about task configuration are pretty low level and can be found here.

Thanks for replying, Noel! I really appreciate it! Thank you and the rest of the team for making such a great program (the amount of tools that you provide to us is unbelievable).