кто сталкивался, помогите Piggy-back tax

Creating a piggy-back tax on top of a national tax. This would be an additional percentage rate added to the existing tax. The amount (percent) of the piggyback tax could be set or limited by national law (to take account of macro-level fiscal situation), but the decision for the piggy-back tax would have to be taken by each local authority.

большое спасибо!