ATC_ INS_ and PSC_ parameter categories

Working through the available documentation on tuning, there appear to be three categories of parameters involved in tuning: ATC_ INS_ PSC_.

I couldn’t find a description that describes the overall function of these categories.

Interestingly, the tuning guide steps directs setting just a couple of INS_ and PSC_ parameters. Most of the initial configuration parameters are ATC_.

Autotune then makes adjustments only to ATC_ parameters. There’s nothing I could find that speaks to improving INS_ or PSC_ parameters for improving a vehicle’s tune.

Am I correct in understanding that there is no guidance on setting INS_ or PSC_ parameters to improve vehicle tune in the wiki?

Some broad brush strokes of information about the function of these parameter categories would help in understanding the various message threads and documentation that bring up these parameters.

Thank you