Flexible vs. fixed oil interval?

Hi,

If I don't have the QG1 PR code on my 1.6 TDI (CLHA).
Do I have to stick to the 15k km oil change interval?

I have some misunderstand meanings of these worlds:
- Fixed Service (Time and Distance)
- Flexible Service (LongLife Service)
- Service Interval Extension (QG1)

Can I use a long life oil or I can not use it without the QG1 option code?

There is a coding for the oil quality: good or poor quality.

What if my car is on Good quality setting by default and I am using a non long life oil and setting my service reminder to 25k km?

Thanks

OK, Now its clear.

I read the service book of my car.
On the first few page it is clearly shown, I had to check if the car have QI1 to QI6 PR codes. I have QI16 what means Oil change within 2 years or when the interval reminder message comes up and I have to use long life oil to change.