In addition to being used to sharing information with organizations, ePACT can also be used for personal use, as a single emergency form. You can create your own ePACT account and invite others to be a part of your support network. That way, trusted friends and family members would be able to access your crucial information (e.g. severe allergies, medications) in the event of an emergency.
If you only wish to be an emergency contact and not create your own personal ePACT account, it's not necessary to fill in your additional details past your basic contact information.
However, don't forget to update your basic contact information (e.g. phone number) if anything changes. As an emergency contact, your contact information should always stay up to date in case of an emergency.