Basically when a user is promoted, they would receive a PM or an email with the body being determined based on the promotion. For example, if a user is promoted to group a, they receive an email that says:
Code:
Hi username,
You have been promoted to group x. Membership in group x gives you access to the following forums:
Blah
Blah
and access to the following features:
Blah
Blah
Thanks,
Board Team
Also, the body of the email should be editable via AdminCp.