improve Icinga2 docs

admin-guide/configuration/monitoring/icinga2.md

@@ -243,6 +243,8 @@ icinga2::custom_service:
 
 Possible commands are [`http`](https://icinga.com/docs/icinga-2/latest/doc/10-icinga-template-library/#plugin-check-command-http), [`tcp`](https://icinga.com/docs/icinga-2/latest/doc/10-icinga-template-library/#plugin-check-command-tcp), [`udp`](https://icinga.com/docs/icinga-2/latest/doc/10-icinga-template-library/#plugin-check-command-udp), [`ssl`](https://icinga.com/docs/icinga-2/latest/doc/10-icinga-template-library/#plugin-check-command-ssl), [`ssh`](https://icinga.com/docs/icinga-2/latest/doc/10-icinga-template-library/#plugin-check-command-ssh) or [`ftp`](https://icinga.com/docs/icinga-2/latest/doc/10-icinga-template-library/#plugin-check-command-ftp).
 
+The actual service name is up to you, it only needs to be unique.
+
 ### Other Custom Checks
 It is possible to create a very custom check. But note the command or service template used needs to be available/configured by some other means on the Icinga Master. The check plugin executed on the Icinga Satellite or by the Icinga agent needs also to be already available or distributed by other means. So please reach out to the [Linux Team](mailto:linux-eng@psi.ch) to check how to do it best and to ensure that all is in place.
 
@@ -255,7 +257,7 @@ icinga2::custom_service:
        file_size_filename: '/var/my/growing/file'
        file_size_warning = '100M'
        file_size_critical = '200M'
-  'My Service Check 1':
+  'My Service Check 2':
      command: 'tcp'
      agent: false
      vars:
@@ -270,4 +272,4 @@ Below `icinga2::custom_service` set the name of the service/service check as it
 - `vars` hash with arguments for the service check
 - `perf_data` if performance data should be recorded and performance graph should be shown, default is `false`
 
-
+You are free in the use of the actual service name, it only needs to be unique.