You can create a rule for a mapping specification or apply a rule to a mapping specification. After you create a rule for a mapping specification, you can make it reusable. You can preview the results of the rule.

You can apply a rule specification as a reusable rule in a mapping specification. A rule specification is the logic that you define to generate a rule. When you compile the rule specification, the Analyst tool converts it to a reusable rule. You can apply this reusable rule to the mapping specification.

When you apply a rule to a mapping specification, the Analyst tool maps a relationship between the columns in the rule to the columns in the target. You can remove the relationship from the rule columns to the target columns. However, the rule columns remain in the mapping specification. You can delete a rule from the mapping specification. The Analyst tool removes the relationship from the rule columns to the target columns and deletes the rule column from the mapping specification.