HONDA Part numbering system logic.

[pekingduck]

Good Day Gents,
I have an interesting question and will like to have your expert opinion.
Honda part number supersession.
From experience of other OEM, usually when there is a minor change to a part ONLY the last digit of the part number changes.
I wonder whether this holds true for Honda.
Air Filter for our CB part # 17210-MEJ-981
The question is:
Can we confirm whether the previous # before the part change/upgrade is 17210-MEJ-980 or is it a complete different filter for other models?

Thanks
Alain

Your original assumption regarding the parts numbering system is correct. The last number is for changes other than a major design change, and as Tev62 offered, is for supplier or packaging or manufacturing process change, but still meets the original design criteria. And they usually start at 0.