We've heard from a few of you that it would be helpful to be able to change the subject of your Email Layouts in the Site Prefs, to include related entities. Currently, this is supported in the Email Body but not for the Subject. So for example, if you are using a short_code for your project name, you can customize your subject line to something like:
{Project:short_code} {subject} [Links: {note_links}]
Vote here to support this feature!