Credit Note Received without GST

A user received a credit note from their supplier for a 30% refund of a detention fee, but the credit note did not include GST. They are seeking clarification on whether this credit note needs to be reported in their GSTR 3B. The consensus is that detention fees are often in the nature of a security deposit and may not attract GST, and therefore, such a credit note might not require reporting in the summary tables of GSTR 3B, which typically cover purchases and sales.