I assume most subscribers are from the UK where field trials are very different than the US. In the US, the retriever is required to wait in a holding blind with the handler, then is called to the line or mat to sit and wait for the marks (birds thrown). Most of the birds are dead birds (usually ducks). Typically there is one "live flyer" shot and 2 dead birds thrown in a triple marking test as an example. Typically there is a marking test on land and a marking test in water. The handler must be silent after he signals the judges for the marks to be thrown, until all the birds are down and the judges verbally tell the handler "dog". So in AKC, with up to 4 marks thrown sequentially, there are cues the handler does to help the dog mark: 1) From the holding blind to the mat, handler and heeling dog walk directly towards the key mark. 2) The dog should not "front-seat" the handler at the line, the handler should have push/pull control, which is difficult if the dog sits too far forward in front of the handler, especially on memory marks. 3) Sit with spine aligned on the first mark or the key mark or the go-bird? Have a plan for your dog. 4) In general, watch the dog, not the marks. 5) The dog should focus on each mark until silently cued by the handler for the next mark (no head-swinging). 6) Before running, watch and learn the judge's cadence for timing of the marks. Know the judges cadence (timing of each throw) and cue your dog with slight handler movement to focus on the next mark. 7) Loud send for long punch bird, soft send for short check-down mark. 8) Correct return--- sit, with spine, head and attitude on the next memory mark. 9) Handler typically does not take bird until dog is aligned correctly and focused for the next memory mark. 10) Marks are always sequential with a delay between each mark. If the dog does not hunt the "area of the fall" and does a "gorilla hunt" but finds the bird, he could be eliminated from competition.