The Action column, that is always required, contains a letter value representing the task to perform, such as “C” for creating objects. You can specify the following letters values:
V—View a record. When importing the record is ignored.
C—Create an object
U—Update all fields for the object specified by the name or key. Any previous values are overwritten.
D—Delete the record specified by the name of key.
Because records that view are ignored on import, it is faster to export all the data, and then modify the records to be changed. Change the action values of the records “U” or “D,” and then import the entire file. The “V” records are ignored, and only those records set to “U” or “D” have any effect.