Tax code in accounting entry against billing document

Hi Experts

Please see the tax code A2  in below accounting entry against a billing document. I want to know from where this tax code is coming.  As I have maintain tax category 1 in material master. I have checked VK13 also, but could not find this tax code A2. Due to this tax code excise duty is going with wrong GL. Please guide

Regards

Parkash chand