Address books are now lists
To align with wider industry terminology, and to reflect the greater variety of data you can store, address books have been renamed to lists. The functionality for lists is identical to the way you are used to working with address books. Any of your existing address books are automatically available as lists, with the same names and unique numeric ids.
Address books are referred to as lists with unified contacts
Adding contacts to lists
You need to use the Contacts API to add contacts to lists; we recommend using Import a single contact for individual updates and Import contact collection for bulk operations. The lists field can be used to specify up to 100 list ids to add a contact to.
Finding contacts in lists and segments
Since Dotdigital adopted unified contacts that can be identified using any associated identifier, such as email, mobile number, contact id etc..., it is important to use the Contacts API for interacting with any contacts. You should use the Get contacts based on your criteria call with the ~listId filter to find contacts in a list, and the ~segmentId can be used for segments.
Finding modified contacts in a list or segment
We recommend using the Get contacts based on your criteria with the ~modified filter used in conjunction with either the ~listId filter or the ~segmentId to find contacts modified after a specific date-time in a list or segment.