The actual syslog appender does not support tags.

As described in the documentation, the facility should be used to identify the source, but the facility is a legacy definition and is quite restricted to do that. In modern setups it is better to use the tag mechanism to identify the source as it support arbitrary data, opposed to the static facilities list. With this it is possible to build centralized logging servers for receiving logging from different applications or cluster nodes from applications. With facilities that cant be achieved as it has limited options (basically only the local0 to local7)

In summary, this feature request is to implement and enable the tag configuration inside the Syslog Appender configuration. As the tag itself does not have a standard format, arbitrary string data should be accepted as a possible tag

Thanks