Yes I agree, same with a caution really I guess. Although as I said earlier, they can't issue a PND for a Byelaw, or not ticketing ones anyway (some other offences that warrant a PND could also be covered by Byelaws such as Section 5 POA to an extent).
If ACPO as it were, to make a PND offence from ticketing, then it would almost definitely be for 5.3(a) RRA 1889 and not a Byelaw, as this is obviously the more serious of the two, and is recordable. They also have to be specific to the legislation they cover.