The following is a description of Scent Discrimination, from the Kennel Club Year Book 2005/2006.
(1) Cloths must be placed in position by a steward and
must be at least 1m (3ft) and not much more than 1.6m (5ft) apart.
(2) The method of taking scent is at the handler's discretion. However, in Class C this shall not require the Judge to place his hand on or lean towards the dog.
(3) In Class C, more than one decoy steward may be used, and each decoy steward is permitted to place a maximum of 2 cloths for each dog.
(4) Decoy stewards must not handle a cloth for longer than the handler in Class B, or the judge in Class C. Cloths must be stored out of reach of the dog whilst not in use.
(5) Any cloth which is fouled in any way e.g. mouthed, must be replaced with a fresh cloth.
(6) At the commencement fo the test the dog must be brought to a designated point. The dog must be facing away from the cloths while scented/decoy cloths are placed in position. When the cloths have been placed, the handler must give the dog scent, stand up straight and send the dog on command from the judge or steward to find the correct cloth. The dog, on finding the correct cloth must then complete the test as for the Retrieve Test.
(7) Limiting the time for this test is at the judge's discretion.