I'm no expert in this field, but to me it seems as if SAS has changed to the 6 characters Amadeus booking from the former "homemade" 5 characters when booking online at SAS' webpage.

Within the last two weeks I have made six bookings, and I now notices, that they are all with 6 characters. Up to November they were all 5 characters.

To me, that’s an improvement, as it is possible to track the booking within the Amadeus-system, especially checkmytrip.com, from where it’s easy to download the trip to my Outlook.

Can anybody elaborate on this change?