SiDiary will use the field "KETONE" to populate the event data type.
This is kind of historical issue since version 5 didn't had the event marker field but the ketone datatype only. Version 6 reused this field and can now handle all of the defined events and store them in that record type.
Note: SiDiary will import all values from the KETONE field as they are given but you should ensure that they match to the KEY-definitions in the event screen (Diabetes Profile->Events)!