multiple type of "VAT" (also negative) and give them name

[kintaro1981]

In case you are going to add multipe types of VAT please:

• make them possibile negative (like the actual VAT field).
• give the possibility to give them specific names (for example in italy in some cases you don't have VAT but "ritenuta d'acconto")

[baimard]

Taken into account, thank you for your interrest !