The form covers enforcement using PCNs under two regulations.
Reg 9 PCNs are served at the roadside, and only informal reps can be submitted against these. A formal representation must be submitted when the council serve the Notice to Owner.This is because the law makes the keeper of the vehicle responsible for PCNs even if not driving. So if reps are submitted, and rejected, and the PCN recipient does not pay-up, the council must issue a Notice to Owner if they want to carry on enforcing.
Reg 10 PCNs cover moving traffic offences, (plus driveaways when a Reg 9 PCN could not be served). These are sent to the keeper of the vehicle, and formal reps (like against an NtO), can be submitted against it. No Notice to Owner is issued, because the PCN is sent to the owner.
So the form covers (1) non-receipt of a Notice to Owner, or (2) non-receipt of a Reg 10 PCN. As your PCN was a Reg 9, you can confidently tick the box for " I did not receive the PCN/Notice to Owner".