It all depends what pages you have selected to print with each copy under the print options
File>Print Options>Global Print Options>control which forms print.
That is where you set every form for each of the 3 copies to either Never, If Required, or If any data.
Sure there is a default, but I can't imagine using that without modifying it to fit what I wish to print.
I seen some comments that some think that what ever prints with the filing copy is what get transmitted to the IRS, seeing that you can change what prints however you want, it makes that thought seem illogical.
