Hi Nicolas,
2.1 - 2.2 - what you suggested is not enough do not solve completely the issue, it should be applied on Tax Rule. Let me explain:
- You created the Tax Rate to have a tax rate % for each value (0%, 17%, 19%, 20% etc.) and, as you wrote, for each one we have a fixed namekey.
- Then, you created the Tax Rules to apply the Tax Rates to Tax Categories in different conditions. So, can happen to have 3 different Tax Rules that are using the same Tax Rate (on different conditions):
--- Tax Rule 1: Taxe Rate A% + Tax Category F + conditions
--- Tax Rule 2: Taxe Rate A% + Tax Category G + conditions
--- Tax Rule 3: Taxe Rate A% + Tax Category Y + conditions
So:
A - your workaround, to add a language string, should be done on Tax Rule (this is I suggested to add like a "Title" Tax Rule field), NOT on Tax Rate (namekey). Because, on invoice I should detail why (usually one word) the IVA % is applied to that product.
B - Otherwise, if I am forced to duplicate the Tax Rates for the same %, have no sense to have the Taxe Rates and you could deprecate that feature by adding a % field just into the Tax Rule
2.3 - So, the fact that I cannot edit the Tax Rate namekey, but if I create a new one with the same namekey of an existing one, with a different Tax %, the old namekey value is overwritten... Is it running as expected ?