The following 4 bullet points are taken from the DSA site and
describe the manoeuvres required from driving instructors for their
Part II exam. The same is true for learners, too.
You must show the ability to perform two of the following
manoeuvres:
- drive the vehicle in reverse gear and whilst doing so enter
limited openings to the left, taking effective all round
observation
- turn the vehicle to face in the opposite direction by the
use of forward and reverse gears taking effective all-round
observation
- reverse park the vehicle into the space behind a parked car,
within the space of about two car lengths and close to and
parallel with the kerb, taking effective all round observation
- reverse park into a parking bay, with due regard for other
vehicles or pedestrians, while taking effective all-round
observation
The full text can be viewed

Do not start any manoeuvre if you can see you cannot complete it.
If the situation changes during the manoeuvre, STOP and see what the
other road user wants to do.
To maintain a slow, steady speed, keep as much
pressure on the foot brake as is necessary to maintain a steady walking
speed (about 3 mph). If going up hill or over the road camber, you might
need to squeeze the gas pedal to get the car moving but then immediately
cover the brake.
Work out where your reference points are. Either i)
ask me or ii) drive somewhere quiet and try each manoeuvre out. Look for
the kerb or other lines and where they meet the bottom or side of a
window.