I am currently experiencing the following issue in my environment, however cannot reproduce on sandbox/demo because they are not set up for outbound email.
Consider an event that is full and is waitlist enabled. When an administrator wants to add someone to the wait list (using civicrm/participant/add) they can select the status of "On waitlist". If you select the option to send a confirmation email, the email looks like the standard event confirmation email and makes no mention of the waitlisted status (as compared to the same user registering themselves for the waitlist online, they properly get an email indicating they are on the waitlist).
Can anyone else reproduce this?
Further, regardless of whether or not someone can reproduce, I am trying to decipher where in the code (in CRM/Event/Form/Participant.php ?) this is happening but haven't made much progress.
Any insight is appreciated.