The macro instruction is the mapplet referenced by the Macro transformation. Every Macro transformation must have a macro instruction.
The Developer tool prompts you to select a mapplet as the macro instruction when you create a Macro transformation. You cannot select a different mapplet as the macro instruction after you create the transformation.
Consider the following rules and guidelines for the macro instruction mapplet:
The mapplet must be a midstream mapplet.
The mapplet must have exactly one Input transformation.