Offline Events is the mechanisms by which you can create custom tables to store information about recipients. Use offline events to store multiple data points, such as all the whitepapers someone has downloaded or their shopping cart abandonments.
These APIs allow you define the offline event as well as populate the new table with recipient information.
Every offline event row is associated with a specific recipient. When you add information to the offline event you must provide the email address of the recipient, in addition to the data for any columns you have defined.
You can designate whether a column can have a null value. If it is defined as requiring a value and a value is not provided when a new row is added, the API call will fail.
Additional columns can be added to the offline event later, but not-null fields cannot be added after any rows have been inserted into the table.
Offline events allow multiple entries for a single recipient, so when updating or deleting rows you need to know the unqiueId value for the row. Other APIs will tell you the value.