In the RRS we use several scoring abbreviations. You can find them in appendix A under A11.
Bence from Hungary has a question about the use of DNF versus DSQ:
we had a course for national judges here in Hungary where there was a presentation in connection with Rule 42 and Appendix P. I became a bit unsure about the following: after the second penalty according to Appendix P, the penalized boat shall leave the race area immediately - that's clear. But which scoring abbreviation is used to indicate this penalty in the results?
I have had several experiences from many countries in Europe. I saw DSQ, DNF and also RAF. As I think, the proper code would be DSQ, because it is a disqualification. RAF is the least proper beacuse the boat retired during the race, didn't finish.
If you have some official information about it, please post it on your blog. I think it is very important to judge this question in the same way all over the world.
I have no official information, other then through deductive reasoning from the RRS and the Manual.
For the first penalty the sailor shall do a Two-Turns penalty under rule 44.2. If she fails to do so, the judges will record that and the scoring will be a DSQ (without a hearing)
The second penalty is to promptly retire from the race. If she fails to do that she shall be scored DNE.
Retiring from the race can also happen if you infringe rule 2 and cause damage or injury like in rule 44.1(b).
The moment you retire does have influence in the scoring abbreviation. If you retire after you have finished, you get RAF, but if you retire before you have finished, you get a DNF.
It also can't be a DSQ because that would be used for a first time 'infringer' failing to do a Two-Turn Penalty.
In my opinion the correct scoring abbreviation for the boat in your Q is: DNF.
Perhaps it should be something that indicated why she did that - in our specific case, because she was yellow flagged for the second time in the regatta - but then we get to the slippery slope of when to indicate the reason for not finishing and when not. It is the same for a boat that retires during the race because she has some gear failure - in opposite to a boat that retires because she caused damage while breaking a rule from part 2. Both get DNF and the reason is not in the abbreviation.
On a final note: If you want to use other abbreviations in the scoring, you need to define them in the Sailing Instructions. ( For instance 'Discretionary Penalty' becomes DPI.) Otherwise use only those in A11.