+The encoding of the TBSCertificate portion of a certificate is cached
+in the B<X509> structure internally to improve encoding performance
+and to ensure certificate signatures are verified correctly in some
+certificates with broken (non-DER) encodings.
+
+Any function which encodes an X509 structure such as i2d_X509(),
+i2d_X509_fp() or i2d_X509_bio() may return a stale encoding if the
+B<X509> structure has been modified after deserialization or previous
+serialization.
+
+If, after modification, the B<X509> object is re-signed with X509_sign(),
+the encoding is automatically renewed. Otherwise, the encoding of the
+TBSCertificate portion of the B<X509> can be manually renewed by calling
+i2d_re_X509_tbs().
+