A certificate provides a representation of its issuer's identity, in the form of a Distinguished Name. The issuer identification is used to select the appropriate issuer public component to employ in performing certificate validation. (If an issuer (CA) is certified by multiple PCAs, then the issuer DN does not uniquely identify the public component used to sign the certificate. In such circumstances it may be necessary to attempt certificate validation using multiple public components, from certificates held by the issuer under different PCAs. If the 1992 version of a certificate is employed, the issuer may employ distinct issuer UIDs in the certificates it issues, to further facilitate selection of the right issuer public component.) The issuer is the certifying authority (IPRA, PCA or CA) who vouches for the binding between the subject identity and the public key contained in the certificate.