Trail Qualities and ETC. (White Giant)

After countless days learning how to configure the Options for the Corporations such as the qualities, I still don't understand. I'm reading the Documentations but i can't quite understand it anyways. I want to know how i use the Trail Quality, It'll have an effect on my Increases and Decreases for each month. So what i'm asking is, If i did the Increase and Decrease for each Corporation manually, Do i need to set the Trail Quality or not? Also, I'd like to know how i can raise my value for Corporations at a high number.

check out Trade Strategies of other countrys corps. experiment.

The ansewer to your question depends on a lot of variables.

In the corporations link> Trade Strategies>
There is a small box to check if you want to follow changes in quality in your sales strat.

If your into making profits and not ripping yourself off, trail quality sale strategy is a MUST.