The D.S.A. set the driving test, and is the only "official" driving test in the UK. Advance drivers have already sat the D.S.A. test and another organisations test as well. It is common practice for advanced drivers (ad) not to signal where no one is going to benefit. On your DSA test if no one is going to benefit your signal then the highway code does say that you don't always need to signal. In fact you could fail if you gave to many signals. Unnecessary signals, badly timed signals can make you fail. I had one pupil who had been taught by her dad, and she came to me just a few weeks before her test. She would signal for anything, overtaking parked cars, signal to move back in, signal to move back out, signal to move back in. One day I decided to try and show her the error of her ways. We drove along a stretch of road that had many junctions on the left. For about 3 miles of this road there are around 23 junctions. I tried to tell her that sometimes signals could be misleading, "but my dad said" was her reply. SO of we went. It started off quite well, she remembered not to signal to move back into her normal driving position. Then it happened, she signalled to overtake a parked bus, passed it and as she looked in her mirror she signalled to move back in and as she was about 20 metres from a junction with a car waiting to come out, out it came. She screamed at him about his stupidity and he could have caused an accident etc.... it was only after I told her that she had her left indicator on as she approached the junction and that HE assumed that she was turning.
After a few days practice she got rid of that bad habit and passed her test first time.
I've sat in on a test for one of my pupils who's dad is a traffic police driving instructor and this lad didn't signal at junctions on at least 2 occassions and still passed. The examiner asked him why he didn't signal and the boy replied there was no one around me at the time.
As I teach both the D.S.A. test and advance driving techniques I can interchange my driving style for both tests ( not easy sometimes).
I also use some AD techniques for my DSA pupils, I want them to survive on the roads nowadays and if it helps them, so be it.
Remember this, Drive like you did on the day you passed your test and you can't go wrong.