We have learned that no matter what we put in the subject line box for a custom Session enrollment message, the name/title on the meeting request line will be "Course Name - Session Name". The learner sees this in the Microsoft Outlook calendar, for example, when they accept the meeting request and add the Session to their calendar.
The combination, "Course Name - Session Name", can run mighty long for some courses. It would deliver a better learner experience if the name/title of the meeting could be customized.