TElCertificateIssuerCRLExtension is a descendant of TElCRLExtension class.
This extension is used to identify the certificate issuer.
The following paragraph is taken from RFC 2459 (Housley, et. al.), part 5.3.4:
«This CRL entry extension identifies the certificate issuer associated with an entry in an indirect CRL, i.e. a CRL that has the indirectCRL indicator set in its issuing distribution point extension. If this extension is not present on the first entry in an indirect CRL, the certificate issuer defaults to the CRL issuer. On subsequent entries in an indirect CRL, if this extension is not present, the certificate issuer for the entry is the same as that for the preceding entry. »