Gets or sets a value indicating whether a certificate whose revocation status no CRL or OCSP response establishes makes the signature Indeterminate (RevocationUnknown). Off by default: missing revocation data is shown in Revocations but not reported as a problem.
public bool RequireRevocationStatus { get; set; }
ISO 32000-2 §12.8.3.4.5 d) and §12.8.3.4.6 ("the revocation status of every certificate ... shall be checked").