System fields are available in the campaign builder that allow you to insert specific content into your campaign, such as web links, unsubscribe links, or links to your campaign's subscription preferences page. These system substitution tags are not related to your contact data and should not be confused with reserved or custom fields.
System Fields, also known as Substitution Tags are available in the campaign builder that allows you to insert specific content into your campaign, such as web links, unsubscribe links or links to your campaign's subscription preferences page. These system substitution tags are not related to your contact data and should not be confused with reserved or custom fields.