Regarding the progression of NOR Rule 1 c iii, I pulled up the oldest NOR I could find on jibeset : 2011. As you can see 1 c iii has been there since at least 2011.
For 2020 we (the SSS Board) decided to rewrite the NOR to discourage the powered behavior, by requiring that the PHRF specifies allowable usage for the powered winches. This was based on a report of a young healthy sailor short-tacking SF using powered winches. If you're not racing you can use all the powered stuff you want. Once you are racing, and you want to use power winches, you now have to have the PHRF committee spell out what you can use for their rating. This was what we did to limit the use of powered winches, somewhat on the reasoning that the PHRF Committee will only give you one rating, so most likely the only person who would ask for this degraded rating would be an SSS-only racer, since other races don't allow powered winches. Any way, here's the cut/paste from over the years:
2011 NOR 1 c iii: Powered winches, hydraulics, or furling devices – only on boats that have declared this information on their PHRF application and have been rated accordingly. This modifies RRS 52.
Remains identical through 2019.
2019 NOR 1 c iii: Powered winches, hydraulics, or furling devices – only on boats that have declared this information on their PHRF application and have been rated accordingly. This modifies RRS 52.
2020 NOR 1 c iii (Jan 1, 2020): Powered winches, hydraulics, or furling devices – only on boats that have declared this information on their PHRF application and have received a PHRF rating that specifies allowable usage for the powered winches.
2020 NOR 1 c iii (Posted around 1/30/2020 for Corinthian race) : Powered winches, hydraulics, or furling devices – only on boats that have declared this information on their PHRF application and have received a PHRF rating that specifies allowable usage for the powered winches. This modifies RRS 52.
At some point prior to Jan 30 I noticed that 1 c iii left off "This modifies RRS 52" and so I added it back in, which is what's posted on the Corinthian jibeset page. Unfortunately there are other versions of the NOR out there that leave out "This modifies RRS 52" but all versions out there have the 2020 change shown above regarding specifying allowable usage.