Publishing Certificates and CRLs
An enterprise CA uses AD to store and publish certificates, complete CRLs, and delta CRLs. Both a standalone CA and an enterprise CA can also publish to the file system. Each certificate published in AD automatically maps to the Windows account of its requestor. AD adds the certificate to the multivalued userCertificate attribute of a user or inetOrgPerson AD object. However, not every certificate that an enterprise CA generates is automatically published in AD. Examples of certificates that aren't automatically published are an enrollment agent or certificate trust list (CTL) signing certificate.
A standalone CA can publish issued certificates to AD, but this step isn't the default behavior. A standalone CA will automatically publish certificates to AD only if an enterprise administrator installs the CA on a member server joined to the domain. You can obviously always publish the certificates manually to AD. . . .