Perhaps all of the following has been discussed previously in these forums, but I didn't search for it. Since I went through the trouble of discovering this, I wanted to share it and also have this information for reference in the future. Also (perhaps I missed it) I did not see this behavior documented in the help site at http://help.totaralms.com/Face-to-face_notifications.htm. This information is all based upon Totara 2.5.6.
One might expect face-to-face notification templates configured at Site administration / ▶ Plugins / ▶ Activity modules / ▶ Face-to-face / ▶ Notification templates to affect all new and/or existing instances of F2F activity modules' notification messages. This is not the case.
When you create a new F2F activity in a course, the notification messages applied to the new F2F instance are based upon the current language strings within the face to face activity module. F2F notification messages are not copied from the F2F notification templates. The notification messages within a newly created F2F activity default to the language strings that existed at the time when the F2F activity was created. Any new changes to F2F notification templates and strings do not change any notification messages in existing F2F activities. Any changes to F2F notification templates also do not affect existing F2F activities.
Why was behavior important to understand in the circumstances I was dealt? Because I was asked if changing the F2F notification templates would change the default notification messages in some 70 existing F2F activities. In this case, the answer was, "no", changing the notification message templates has no effect whatsoever on existing instances the F2F activity. At first I thought that new F2F activity's default notification messages were based on the F2F notification templates, but after some exploration I realized that the default messages are based on language strings.
In conclusion, if you want to change the default F2F notification messages that are applied to newly created F2F activities, then you must customize some language strings in the facetoface.php language strings module. If you want to update all notification messages in all currently existing F2F activities in a batch, then you must perform some SQL queries (which we ended up doing). If you have a small number of F2F activities, then changing each message via the user interface definitely works.
I definitely appreciate any corrections or additional information anyone may have.
Finally, if you want to change the F2F default notification messages, then look for the following language strings for customization:
defaultcancellationinstrmngrdefault
defaultcancellationmessagedefault
defaultcancellationsubjectdefault
defaultdeclineinstrmngrdefault
defaultdeclinemessagedefault
defaultdeclinesubjectdefault
defaultconfirmationinstrmngrdefault
defaultconfirmationmessagedefault
defaultconfirmationsubjectdefault
defaultdatetimechangemessagedefault
defaultdatetimechangesubjectdefault
defaultreminderinstrmngrdefault
defaultremindermessagedefault
defaultremindersubjectdefault
defaultrequestinstrmngrdefault
defaultrequestmessagedefault
defaultrequestsubjectdefault
defaulttrainerconfirmationmessagedefault
defaulttrainerconfirmationsubjectdefault
defaulttrainersessioncancellationmessagedefault
defaulttrainersessioncancellationsubjectdefault
defaulttrainersessionunassignedmessagedefault
defaulttrainersessionunassignedsubjectdefault
defaultwaitlistedmessagedefault
defaultwaitlistedsubjectdefault