Oracle provided jar files that come with Oracle Forms 11g and 12c were signed out-of-the-box with a java feature called Timestamp.
For an Oracle Forms user, this means that Security Warnings related to certificate expiration should not occur even after a certificate has expired.
The only indication of a certificate expiration would appear in the Java Console and look like this:
security: Validate the certificate chain using CertPath API
security: The certificate has expired, need to check timestamping info
security: Timestamping info is available
security: The certificate has expired, and is timestamped in valid period
security: Start checking TSA certificate path
More details about this feature are described in: Doc ID 2072400.1