The communications generated via the GST common portal already include a Reference Number (RFN), which is verifiable online and provides essential document details such as issuance date, type, and originating office. As per Section 169 of the CGST, serving documents electronically through the common portal fulfills statutory requirements, rendering additional DIN quoting redundant. It emphasizes that RFN- bearing communications are valid without DIN, streamlining the process while maintaining traceability.