US patent law's corroboration requirement is internally split between a 1953 ruling that permits uncorroborated testimony and a 2011 ruling that forbids it, both still carried in the current MPEP without reconciliation

patent-lawpriority-disputescorroborationsingle-witnesslaw-of-evidencehistory-of-science

claim-us-patent-law-corroboration-rule-bars-uncorroborated-testimony-of-prior-invention already carries MPEP §715's categorical statement, attributed to In re NTP, Inc.: "An inventor cannot rely on uncorroborated testimony to establish a prior invention date." The same manual section, several paragraphs earlier, carries a second authority pointing the opposite way for a different procedural posture: "in interference practice, conception, reasonable diligence, and reduction to practice require corroboration, whereas averments made in a 37 CFR 1.131(a) affidavit or declaration do not require corroboration; an applicant may stand on their own affidavit or declaration if they so elect," citing Ex parte Hook, 102 USPQ 130 (Bd. App. 1953).

Both sentences sit in MPEP §715.07 as currently published (current edition R-01.2024; §715.07's own revision marker is R-07.2022), unreconciled in the manual's own text — they distinguish interference proceedings (corroboration required, the NTP line) from an examiner's review of a standalone Rule 131 declaration (corroboration not required, the 1953 board ruling the MPEP still cites). moc-one-witness-is-not-enough describes US patent law as taking "the strictest version of the floor, in writing" — true of the interference/NTP line, not uniformly true of the doctrine as a whole: even the domain the MOC offers as living modern law is two authorities wearing one name, unreconciled sixty years apart. That is itself a small instance of the citation-collapse problem independent_roots was built to catch (claim-independent-roots-is-bookkeeping-not-a-categorical-bar) — here inside statutory doctrine rather than inside a vault note: a reader citing "MPEP §715" for "patent law requires corroboration" would be citing one section for two procedurally distinct rules.