Identifer: core.acp_email_send_before
Location: Before sending all emails in the for loop. I'd like to modify the template so there has to be a variable for that before the loop as well. Same for modifying the template vars. Not for me but I could also imagine that some want to modify the subject.
You can maybe even change the added log, so there might be an extra variable for that too. We don't need an extra event then later.
Parameters: $email_template, $template_vars, $subject, $log_entry
Explanation: For using a custom email template for some cases, adding some vars to it, which can be used then, and changing the subject (for example by adding a prefix or similiar). And adding a customized log entry.
Ticket: https://tracker.phpbb.com/browse/PHPBB3-13312
EDIT: added the log entry
Further: Added ticket