C<$params{is_sales}>) or expense (for falsish values of
C<$params{is_sales}>) account for the current part. It uses the part's
associated buchungsgruppe and uses the fields belonging to the tax
C<$params{is_sales}>) or expense (for falsish values of
C<$params{is_sales}>) account for the current part. It uses the part's
associated buchungsgruppe and uses the fields belonging to the tax