= /Expenses:Transportation/ and not expr "has_tag(/NOTAX/)"
         Expenses:Tax                     0.2
         $account                        -0.2

2020-05-06 * Test
    Expenses:Transportation            200.00 EUR
    Assets:Bank                       -200.00 EUR

2020-05-06 * Test
    ; :NOTAX:
    Expenses:Transportation            300.00 EUR
    Assets:Bank                       -300.00 EUR

test bal
         -500.00 EUR  Assets:Bank
          500.00 EUR  Expenses
           40.00 EUR    Tax
          460.00 EUR    Transportation
--------------------
                   0
end test