psd= tag
The DMARC tag from RFC 9989 that says whether a record belongs to a public suffix domain (y), an organizational domain (n), or is undetermined (u).
What it means
psd= helps receivers find the organizational domain during the DNS tree walk. Operators of public suffixes, such as a registry for a top-level domain, publish psd=y so receivers know registered names one level below are separate organizations. psd=n declares the record's domain to be an organizational domain for itself and everything below it, which lets a large company draw its own boundaries. The default, u, leaves the decision to the tree walk.
Most domain owners never need it. It matters to registries and to organizations whose subdomains are run by independent units.
RFC 9991 forbids report generators from acting on ruf= in a record carrying psd=y unless the parties have agreed otherwise.
Example
v=DMARC1; p=reject; psd=n; rua=mailto:dmarc@example.comRelated terms
Sources
What this definition rests on. The wording is ours; the facts are theirs.
All 432 terms in the glossaryThe wiki: blocklists and bounce codes