The only variables available for email notification subject lines are %JobResult%, %JobName%, %VmCount%, %Issues% and %Time%. It would also be useful to be able to see whether the job was a full backup, incremental, etc. Currently, the only clue about this is in the heading of the table in the message body. If it's a full backup, it says "(Full)" after the job name. If it's an incremental, it doesn't add anything after the job name.
Is there any way to get it to add the job type to the subject line, or even the body?