For instance, ``FILE:<filename>`` can be used to point to a specific file.
This parameter can be specified only once, in the parameters scope,
and is the equivalent of setting the ``KRB5_CLIENT_KTNAME`` environment
- variable.
+ variable. The empty value is silently ignored.
- ``credentials-cache`` specifies the Kerberos credentials cache.
For instance ``FILE:<filename>`` can be used to point to a file or
``DIR:<directory-path>``.
This parameter can be specified only once, in the parameters scope,
and is the equivalent of setting the ``KRB5CCNAME`` environment
- variable.
+ variable. The empty value is silently ignored.
- ``server-principal`` is the Kerberos principal name of the DNS
server that will receive updates. In plain words, this is the