Furthermore, there are parts of the Welsh Tax Acts where specific regulation-making powers were not taken; in LTT one key area is the provisions relating to the calculation of tax.
At hynny, mae rhannau o Ddeddfau Trethi Cymru lle na chymerwyd pwerau penodol i wneud rheoliadau; yn y dreth trafodiadau tir, un maes allweddol yw'r darpariaethau sy'n ymwneud â chyfrifo treth.