You've seen a DMARC record with t=y and don't recognize the tag — or you're wondering whether the pct= tag you've always used still works.
RFC 9989 (the DMARCbis core standard) retires the pct tag — IANA's DMARC Tags Registry now lists it as “historic” — and registers a new t tag with status “active”, described as “DMARC policy test mode”. The t tag is binary (y/n, default n) rather than a percentage, and it steps enforcement down exactly one level for a domain owner who is still testing: with t=y, a policy of reject is applied as quarantine, and a policy of quarantine is applied as none — it has no effect once the policy is already none, and it doesn't change report generation. Source: RFC 9989, Record Tags (“t:”) and the IANA DMARC Tags Registry (pct=historic, t=active) · verified 2026-07-17.
pct=, keep it — RFC 9989 retiring the tag doesn't break existing records; receivers that haven't updated their parsers keep honoring it.t=y over a low pct= value while validating a quarantine or reject policy — one flag instead of a percentage, and it's what the current standard defines.t=y with p=none expecting extra caution — the tag has no effect when the policy is already none.t tag before relying on it — RFC 9989 is only months old.No, not immediately. RFC 9989 keeps the same v=DMARC1 tag syntax your current record uses — it mainly changes how receivers discover the record (the DNS Tree Walk) and adds optional new tags like t= and np=. Nothing about your existing record becomes invalid.
No — RFC 9989 explicitly obsoletes RFC 7489 as a refinement of the same DMARC standard, based on years of implementation experience. Aggregate and failure reporting moved into their own documents, RFC 9990 and RFC 9991, all published May 2026.
RFC 9989 (core), RFC 9990 (aggregate reports) and RFC 9991 (failure reports) are all published free at rfc-editor.org, no registration required.