If PIS is between 100 and 350 and externally/independently compiled, you must submit FAS, but you may choose to submit AFS
If PIS is below 100, then submit FAS
If PIS between 100 and 350 and internally compiled, this triggers an audit, and AFS must be submitted
Disclaimer:
Please note that the information provided does not constitute legal or professional advice, but rather the applicability of existing theory to a given practical situation. Due care is taken to ensure that the information is correct, but it remains subjective and an interpretation of application of information.