Use the Outputs List to organize the outputs you want to render from Action. You must have at least one output in the Outputs List. By default, a Comp output exists, which is set to render the entire comp and result camera.
When you save an Action setup, your outputs are also saved.

Lists all of the existing render layers. Use the buttons below to populate the list with the render layers you want. To deselect an render layer from rendering (but keep it in the list), click the yellow arrow beside the output.
Adds a new render layer to the list. Use the Rename button to change the name to something more meaningful.
Creates a copy of a selected render layer.
Deletes the selected output from the list.
Opens the onscreen keyboard to rename the selected render layer in the list. Renaming a Render Layer automatically renames all output sockets enabled from that Render Layer.