This tool is super useful to get acquainted with relabeling rules, so it
should be mentioned before we dive into more examples. This way ppl can
start playing with relabeling rules faster and even test our examples.

service/prometheus.md

@@ -1472,6 +1472,13 @@ which changes labels before the scrape is performed, so that the
 blackbox exporter is scraped instead of the configured target, and
 that the configured target is passed to the exporter.
 
+The site [relabeler.promlabs.com][] can be extremely useful to
+learn how to use and iterate more quickly over those configurations. It takes in
+a set of labels and a set of relabeling rules and will output a diff of the
+label set after each rule is applied, showing you in detail what's going on.
+
+[relabeler.promlabs.com]: https://relabeler.promlabs.com/
+
 There are other uses for this. In the `bacula` job, for example, we
 relabel the `alias` label so that it points at the host being backed
 up instead of the host where backups are stored:
@@ -1547,9 +1554,6 @@ normal `node` exporter, which made it impossible to (say) avoid
 sending alerts about a catalog being stale in Puppet because a host is
 down. See [tpo/tpa/team#41642](https://gitlab.torproject.org/tpo/tpa/team/-/issues/41642) for a full discussion on this.
 
-The site [`relabeler.promlabs.com`](https://relabeler.promlabs.com/) can be extremely useful to
-iterate more quickly over those configurations.
-
 Note that this is not the same as [recording rules](https://prometheus.io/docs/practices/rules/#recording-rules), which we do
 not currently use.