All certificates are now required to be logged in publicly available logs (aka "Certificate Transparency").
Since January 2015, Chrome has required that Extended Validation (EV) certificates be CT-compliant in order to receive EV status.
In April 2018, this requirement will be extended to all newly-issued publicly-trusted certificates -- DV, OV, and EV -- and certificates failing to comply with this policy will not be recognized as trusted when evaluated by Chrome.
In other words: if Chrome encounters a certificate, issued after April 2018, that isn't signed by a Certificate Transparency log, the certificate will be marked as insecure.
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