How can the indicators [32b] and [34a] of form 01/GTGT in Circular 89/2026/TT-BTC be understood? These are two new indicators appearing in the section for Goods and services sold subject to VAT ([27]=[29]+[30]+[32]+[32a]-[32b] and Total revenue and VAT of goods and services sold ([34]=[26]+[27]+[34a]).