Populating mapping specifications with shared data rule definitions

There are two ways you can populate a mapping specification:

Create a mapping specification from an existing rule description or rule expression. Create a shared data rule definition from an existing rule description or rule expression. See Creating mappings from shared data rules.
Drag-and-drop an existing data rule definition from the data rules browser into the rule description or rule expression field within the mapping editor. Doing this automatically creates a link to the shared data rule. See Reusing transformation rules.