Numista numbers for varieties

IMO,
Numista number, as it is, is not enough, for it links to a coin, but not to any variety of it.
Like here:
N#20604

Maybe numista should be, as discussed, something like #####A.X, where # is the current number, A a letter(s) to assign a variety, year, etc… and X a number, if needed, for any extra cataloging requirement. 
I think that that´s interesting, lets say, in the scenario where  we have ####A.1 and ####A.2, but need to add a variety between them. That could be ####A.1, ####A.11, ####A.2, so no number would have to change.

So, in the case of the chinese coin above, they would be:
20604.AA.1
20604.AA.2
20604.AB.1
20604.AB.2
20604.AB.3
20604.AC.1

20604.AC.2

20604.AC.3

20604.AC.4

20604.AC.5

20604.AC.6

I like to mix letters and numbers because when a letter changes, we can spot the change faster, without having to read it all.

Here in Brazil for example, Bentes catalogue works with ###.X, where # is the coin number and X (starting from 01) is the counting digits for the year, so a coin minted from 90-98 would be ###.01 - ###.08, so every single entry has it´s own particular number.

Km, for me, has the problem of repeating itself, meaning, all countries have a Km#1,2,3,etc… coin, a problem solved by numista number.

 

I think stuff like this was talked about ad infinitum in the thread(s) about the introduction of the Numista number.

What is a variant, how do you deal with new found variants? etc. pp. Conclusion it would be a pain in the butt to upkeep and Numista is not a printed catalog anyway (ergo bad for longtime continuation).

You can of course use the specific key for the individual yearline but you have not many ways to interact with it at the moment.