In scriptable email template, how does one reference the Expected Release Date of a Product Version?

Documentation on referencing fields in the scriptable template is sparse. A big help would be some SuiteAnswers article explaining even hack methods to determine names to use in scriptable templates. Using the system email template, Standard Issue Notification Email for Employees 2.0, as my base template, I'm trying to reference the Expected Release Date similar to the way Build and Version are already referenced, but I don't know the field name to use. I can see the scriptable field name is dtentative, but that didn't work and I'm aware that references to fields via scriptable templates do not always match references in scripts. I've tried version.dtentative, version.date, version.targetDate, version.expectedDate, version.expectedRelease and version.expectedReleaseDate.