clarification for external ssl termination

docs/installation-and-operations/configuration/ssl/README.md

@@ -63,7 +63,7 @@ This will execute `certbot renew` every day at 1am. The command checks if the ce
 
 ## External SSL termination
 
-If you terminate SSL externally before the request hits the OpenProject server, you need to let the OpenProject server know that the request being handled is https, even though SSL was terminated before.   This is the most common source in problems in OpenProject when using an external server that terminates SSL.
+If you terminate SSL externally<sup>1</sup> before the request hits the OpenProject server, you need to let the OpenProject server know that the request being handled is https, even though SSL was terminated before.   This is the most common source in problems in OpenProject when using an external server that terminates SSL.
 
 Please ensure that if you're proxying to the openproject server, you set the HOST header to the internal server. This ensures that the host name of the outer request gets forwarded to the internal server. Otherwise you might see redirects in your browser to the internal host that OpenProject is running on.
 
@@ -83,3 +83,6 @@ If you're terminating SSL on the outer server, you need to set the `X-Forwarded-
 
 
 Finally, to let OpenProject know that it should create links with 'https' when no request is available (for example, when sending emails), you need to set the Protocol setting of OpenProject to `https`. You will find this setting on your system settings or via the rails console with `Setting.protocol = 'https'`
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+_<sup>1</sup> In the packaged installation this means you selected "no" when asked for SSL in the configuration wizard but at the same time take care of SSL termination elsewhere. This can be a manual Apache setup on the same server (not recommended) or an external server, for instance._