Document Identification Number (DIN) requirement relaxed where verifiable Reference Number (RFN) on common portal suffices. Quoting of Document Identification Number (DIN) is not required on communications issued through the GST common portal that bear a verifiable Reference Number (RFN), since the RFN is electronically verifiable and provides requisite document metadata; earlier Board circulars mandating DIN are modified to that extent and such RFN-bearing portal communications are to be treated as valid electronic communications without DIN.