A Resource Question??

I have seen a few mod in the addon PTW that have resources with more than one set of FSC (food, Shield, Commence) numbers.
example: Cattle: starts with f 2 s 0 c 0, but after discoveing medicine Cattle charges to f 12 s 0 c 0. This allows the resources to change and update over time.

I have tried to recreate this, but I getting a error message.
the message says cannot use the name more than once.
I searched the text files, but could not find anything that would allow the double naming!
I am trying to add this to my mod, can anyone point me in the right direction?

Wow, I have not heard of this, but it sounds exceptional.

My initial thought on how to create this would simply be to name a different type of resource but have it represented by the same icon. Upon discovering the technology, the resource would change to the new stats.

But, upon more thought, it occurs to me that would only give you a new resource in a different location than the old one, and you'd still be left with the old one with the old stats.

If you definitely have seen this, I very much would like to know how this is accomplished as well. It would make for some very worthwhile modding!

TETurkhan mods is where I have seen this. I am going to change the status of the resources and try to see how it works.

Well did my first test, changed the advancements to Alphabet and added the resources. I added the low resources to see if they would change into the high one. They did not, but the others appeared. The High valued resources placed by the creator. So, I had low value resoures and high valued together. One resource with food value of 4 and the other food value of 12.
They both had the same name, but different values. I still do not understand how the double resources were created, but the above test proves you still need two locations. So calling one resource fish and the other fishs will work just the same.

Maybe this could be added to the next patch or addon. Different levels to the resources. example in real life is the American farmers. producing 80% more food today, on 40% less land.
So resources will move up and down with the time and governments. just a thought!