Inputs to any confirmation rule are as follows:
Use userview for a full view of an Identity Manager user.
Use account for a Map of action fields.
A confirmation rule returns a string-form Boolean value of true if the user matches the action fields; otherwise, it returns a value of false.
A typical confirmation rule compares internal values from the user view to the values of the action fields. As an optional second stage in correlation processing, the confirmation rule performs checks that cannot be expressed in a correlation rule (or that are too expensive to evaluate in a correlation rule).
In general, you need a confirmation rule only for the following situations:
The correlation rule may return more than one matching user.
User values that must be compared are not queryable.
A confirmation rule is run once for each matching user returned by the correlation rule.