When you are building a rule, the rule wizard will present you with a number of cases whose interpretation may change due to the new rule. These cases are called Cornerstone Cases. It is therefore very important for you to review each of these cases in turn, and to decide whether you want the interpretation of each case to change
or not.
Normally you will not want the interpretation of the Cornerstone Case to change. You will therefore press the ‘Do not apply‘ button on the cornerstone case screen, and enter a further condition that will restrict the rule you are adding. That is, the extra condition will be false for the Cornerstone Case, so its interpretation won’t be affected by your new rule. The condition must, of course, be true for the current case you started the rule session with.
There may be occasions however when you want the interpretation of a Cornerstone Case to change as well. In this situation you press the ‘Apply change to cornerstone‘ button, which will then skip this Cornerstone Case, and show you the next one if there are any more to review.