https://help.tallysolutions.com/docs/te9rel60/Tax_India/VAT/Assam/AS_Ret_Txn_Book.htm

Return Transaction Book (Assam)

The Return Transaction Book displays the list of saved returns. Each time the Form 13 or CST Form III is modified and saved, the details are displayed as a separate row in this book. The Return Transaction Book appears as shown below:

If Yes is displayed in Is Modified column of this report, the Form VAT 13 report displays a message about the changes made in the return, and prompts you to recompute the values.