184.108.40.206.3.2.13 PropID = 0x0000000D (CR_PROP_CASIGCERTCHAIN) "CA signing certificate Chain"
The client has requested a particular signing certificate and its complete chain. The CA SHOULD retrieve the CA certificate from the Signing_Cert_Certificate column in the row indexed by the value of the PropIndex parameter. The CA SHOULD return the chain of this certificate as specified in [RFC3280] section 3.2. The CA MUST return the certificate chain through a CERTTRANSBLOB (section 220.127.116.11) structure.
Marshaling rules for the CERTTRANSBLOB structure are specified in section 18.104.22.168.