Although an operator on this or on a neighboring IS-IS router has configured the setting of the IS-IS administrative tags, it does not have any effect unless policies are configured to instruct how to process the specified tag value.
Policies can process tags where IS-IS is either the origin, destination or both origin and destination protocol.
config>router>policy-options>policy-statement>entry>from
config>router>policy-options>policy-statement>entry>action tag tag-value
config>router>policy-options>policy-statement# default-action tag tag-value