This policy setting allows you to specify which DNS host names and which DNS suffixes are mapped to a Kerberos realm.If you enable this policy setting you can view and change the list of DNS host names and DNS suffixes mapped to a Kerberos realm as defined by Group Policy. To view the list of mappings enable the policy setting and then click the Show button. To add a mapping enable the policy setting note the syntax and then click Show. In the Show Contents dialog box in the Value Name column type a realm name. In the Value column type the list of DNS host names and DNS suffixes using the appropriate syntax format. To remove a mapping from the list click the mapping entry to be removed and then press the DELETE key. To edit a mapping remove the current entry from the list and add a new one with different parameters.If you disable this policy setting the host name-to-Kerberos realm mappings list defined by Group Policy is deleted.If you do not configure this policy setting the system uses the host name-to-Kerberos realm mappings that are defined in the local registry if they exist.