Each object is a canonical binary encoding, a version byte, and a text form: a prefix plus base64url without padding. Decoding is strict, so an object has exactly one encoding. Every signed format has its own personalization, so a signature for one purpose is never valid for another. A link puts the receipt in the #fragment, which browsers don’t send to the page’s host, with an h= block hint. A link is about 7 KB; some chat apps cut long ones, so the page also saves a receipt as a file and opens one. The prefix was zrcpt1 early on, which clashed with another project’s incompatible text format (zreceipt). It moved to zip311r1 on 2026-10-22, and the verifier recognises a zreceipt link and says what it is. The normative text is docs/ZIP311-ORCHARD.md and the extensions are docs/SPEC.md.