Quick answer
For internationally trained speech pathologists, Grade B (350) in each of the four OET sub-tests is accepted for HCPC (UK, registered as Speech and Language Therapist) and AHPRA (Australia) registration. AHPRA's minimum for Writing is Grade C+ (300); Listening, Reading and Speaking stay at Grade B. The Writing sub-test tests your ability to communicate dysphagia and communication findings to a non-specialist addressee in 250 words of prose. Most marks are lost on Genre & Style: uncontextualised IDDSI codes and dysphagia classifications.