Air Scent Dog - An air scenting dog works by finding human scent that is primarily airborne (hence the term). Once this dog finds the scent cone he follows the scent to its source. The dog is trained to indicate any source of human scent in a given area. This is ideal in an area of wilderness where few humans are present and one must find anyone in the area. The dog works off-lead, usually ranging a good distance away from the handler. However, the dog must always be under the handler's control via verbal commands and hand signals and must possess a strong trained alert to notify the handler of a find.

Alert – There are two kinds of alerts; (see the trained alert and the natural alert).

Cadaver Dog - (See Human Remains Detection Dog)

Forensics Dog - The forensics dog is a sub-specialty of the human remains detection dog. The important distinction is that this dog is able to also identify and indicate on forensic evidence, primary crime scenes, and skeletal remains, in addition to decomposing material, which is much easier to detect than the subtle scent of bone. A forensics K9 should also be able to target scent and pinpoint the source for the handler.

Hasty Search - A hasty search is a non-thorough search conducted to check out a large area quickly. The handler will read his dog carefully to see if he gives any natural alerts.

Human Remains Detection (HRD) Dog - The HRD K9 is a dog that has been trained in the specialty of locating the scent of decomposing human tissue. The dog may be asked to locate a whole corpse (as in a missing person presumed dead), or only body parts from catastrophic trauma such as airplane crashes, or foul play with resultant body dismemberment. This dog may also be taught to locate drowning or submerged subjects through either shoreline work and triangulation methods, or may work from a boat (see water search).

K9 Grid Search - This is a search pattern where the dog is worked perpendicular to the wind in a weaving, zigzag motion. The distance between sweeps will be determined by the handler depending on the scent conditions and typically vary between 25 yards (for poor conditions) to 100 yards or more (for good conditions).

LKP - LKP is an acronym for "last known place". This is the last known location of the subject which can be determined by physical evidence such as a discarded object, footprint, etc..

Natural Alert - An alert is a visual cue as perceived by the handler that their dog has detected human scent. The dog's body language is the "alert." Some dogs have very subtle alerts requiring the handler to be in-tune to the dog’s every mannerism and each nuance of his movement, while others telegraph their alerts so greatly that even a novice would be able to tell that the dog has located a scent. The term "alert" is often used interchangeably with the term "indication".

PLS - PLS is an acronym for "place last seen". This is the last location where the subject was seen.

POA - POA is an acronym for "probability of area. This is an educated guess by search management of the probability that the subject is in a given area.

POD - POD is an acronym for "probability of detection. This assessment is given by the K9 handler after working his assigned area. It is the probability that if the subject was in his search area that his dog would have detected the subject's scent. Several factors can influence this assessment including wind speed and direction, terrain, sunlight, temperature, time of day and the topography of the assigned area.

Reading the Dog - Observing the dog's behavior closely to detect an attitude change, head "pop" or other clue that the dog has encountered human scent.

Refind – When an air scenting dog has found a subject and has given his handler a trained alert, he will lead the handler back to the subject. The distance can range from fairly close to several hundred yards.  

Scent Article – An article which contains the scent of the target subject. It is important that the only human scent contained in this article is that of the target subject. A dog is said to be "scented" when he is allowed to smell this article and then given his search command to find that person. A scent article is used only for a scent discriminating dog. 

Scent Cone - Scent molecules disperse outwards from their source in a conical pattern, forming a scent cone downwind of the subject. An air scenting dog normally works across or into the wind until he locates the scent cone. At this point the dog will give a natural alert, and will begin working his way into the funnel of the cone until he reaches the source, which is the subject. The dog will then notify his handler of the find by giving a trained alert.

Scent Discrimination - The ability of dogs to differentiate one scent source from another. This is typically used in tracking/trailing dogs, but is also utilized in air scenting dogs as well. This is a big advantage in areas where there are a lot of people (i.e. urban areas, etc.).

Tracking Dog - A tracking dog normally works in a tracking harness and line. This dog uses scent discrimination and is “scented” on a scent article of the subject. This dog is best used when the last whereabouts of the missing person is known. This location can be either the point last seen (PLS) or the last known place (LKP). The dog is brought into the vicinity of the PLS/LKP in the hopes that he will be able to pick up the track of the missing person. The dog will track with its nose to the ground, primarily focusing its attention on the subject’s scent and crushed ground vegetation.

Trailing Dog - A trailing dog works similarly to a tracking dog. This dog is scent-discriminating, so a scent article is needed. It is a dog that follows the scent of its subject, but does not necessarily follow each footstep. Instead, this dog follows the scent trail that has been left as the subject traveled. This trail will often be beside or near the actual path, as the scent travels slightly downwind and collects on vegetation, ground, fence lines, etc. Usually this dog is worked on a harness and tracking line.

Trained Alert – A trained indication by which a dog notifies its handler of a find. It is the dog's way of telling its handler, "I’ve found!" Quite often the term is used interchangeably with the term "indication." There are bark alerts, passive alerts (such as when the dog lies down or sits), body slams, and others. The trained alert is used in conjunction with the refind.

Water Search – When a person drowns, scent components (skin, particles, perspiration, skin oils, and other gaseous components) break down during decomposition and bacterial action and rise up through the water until they reach the surface. Once on the surface, the scent particles are dissipated by the breeze and current. A dog trained in water search can detect these scent particles and indicate to the handler the direction to the source in the same manner as an air scenting dog indicates scent during a wilderness search. This type of dog can be deployed on shore, but are better worked from a boat.