Question: What type of weapon did a British Royal Marine help a soldier and firearms expert create?

full_context: Document 1: Kara-Ho Kempo: Kara-Ho Kempo (the unity of spirit, mind, soul and body, fist law) is a martial art created in the 1930s by the late William Kwai Sun Chow of Hawaii (July 3, 1914 - September 21, 1987). The system can best be described as a series of rapid strikes (punches and kicks) to the vital areas of an opponent. The system calls for an equal use of both the hands and feet and, also, teaches self-defense techniques against weapons and multiple attackers.
Document 2: Roy Farran: Major Roy Alexander Farran DSO, MC & Two Bars (2 January 1921 – 2 June 2006) was a British soldier, politician, farmer, author and journalist. He was highly decorated for his exploits with the Special Air Service (SAS) during World War II. Farran became widely known after being court martialled on a charge of murdering an unarmed 16-year-old member of the Jewish underground group Lehi during his command of an undercover Palestine Police unit. After his brother was killed in a revenge attack, Farran emigrated to Canada where he forged a successful business and political career, holding a seat in the Legislative Assembly of Alberta from 1971 to 1979 sitting with the Progressive Conservative caucus. He served as a cabinet minister in the government of Premier Peter Lougheed during that period.
Document 3: FitzGerald Special: The FitzGerald Special, "Fitz Special", or "Fitz Colt" is a snubnosed revolver modified for concealed carry. The concept was pioneered by John Henry Fitzgerald (also known as J.H. Fitzgerald, J. Henry Fitzgerald, and "Fitz"), an employee of Colt Firearms from 1918 to 1944. Fitzgerald was a well known and respected competition pistol shooter of the 1920s and 30s and a theorist and innovator of combat pistol shooting tactics. In 1930, he wrote a book titled "Shooting", on the topics of pistol shooting techniques and tactics. There are "authentic" Fitz Specials modified by Fitzgerald himself, though the term can more generally refer to any revolver with similar modifications.
Document 4: Modern technique (shooting): The modern technique (abbreviation of modern technique of the pistol) is a method for using a handgun for self-defense, originated by firearms expert Jeff Cooper. The modern technique uses a two-handed grip on the pistol and brings the weapon to eye level so that the sights may be used to aim at the target. This method was developed by Cooper into a teachable system beginning in the 1950s, based on the techniques of shooters like Jack Weaver and others, after experiments with older techniques such as point shooting. The method was codified in book form in 1991 in "The Modern Technique of the Pistol" by Gregory B. Morrison and Cooper.
Document 5: Ancillary weapon: An ancillary weapon is a weapon used for secondary or auxiliary purpose, such as a bayonet, combat knife or an officer's side arm. Through until the early 20th century, an officer's side arm was typically a sword or saber, with the inclusion of a revolver between the late 19th century to World War I and since World War II, a semi-automatic handgun. Some soldiers such as Special Forces soldiers whose main weapon is a rifle may also carry a pistol as a side arm.
Document 6: Swiss Army knife: The Swiss Army knife is a pocketknife or multi-tool manufactured by Victorinox AG (and up to 2005 also by Wenger SA). The term "Swiss Army knife" was coined by American soldiers after World War II due to the difficulty they had in pronouncing "Offiziersmesser", the German name.
Document 7: Ek Commando Knife Co.: Ek Commando Knife Co. or Ek Knives is an American combat knife brand produced by several different companies since the original founded by John Ek in 1941. In May 2014 the Ek brand as purchased by Ka-Bar which began selling its versions of Ek knife designs in 2015. Although not officially issued gear, Ek Knives have seen use by US forces in six major conflicts: World War II, the Korean War, the Vietnam War, the Gulf War, Afghanistan, and the Iraq War. Ek Knives manufactures Bowie-style blades, daggers, and a Fairbairn-Sykes MkII. President Franklin Delano Roosevelt, Clark Gable, and General George S. Patton have been identified as Ek knife owners.
Document 8: Krav Maga: Krav Maga ( ; Hebrew: קְרַב מַגָּע‎ ] , "lit." "contact-combat") is a military self-defense system developed for the Israel Defense Forces (IDF) and Israeli security forces (Shin Bet and Mossad) that consists of a combination of techniques sourced from Boxing, Wrestling, Aikido, Judo, Karate along with realistic fight training. Krav Maga is known for its focus on real-world situations and its extreme efficiency and brutal counter-attacks. It was derived from the street-fighting experience of Hungarian-Israeli martial artist Imi Lichtenfeld, who made use of his training as a boxer and wrestler as a means of defending the Jewish quarter against fascist groups in Bratislava, Czechoslovakia in the mid-to-late 1930s. In the late 1940s, following his migration to Israel, he began to provide lessons on combat training to what was to become the IDF.
Document 9: Eric A. Sykes: Eric Anthony Sykes (5 February 1883–12 May 1945), born Eric Anthony Schwabe in Barton-upon-Irwell, Eccles, Greater Manchester, England, was a soldier and firearms expert. He is most famous for his work with William E. Fairbairn in the development of the eponymous Fairbairn-Sykes Fighting Knife and modern British Close Quarters Battle (CQB) martial arts during World War II. Originally working for an import/export company selling weapons in East Asia, he claimed he volunteered for and served in the British Army as a sharpshooter on the Western Front during World War I. Returning to China in 1917, he joined the volunteer branch of the Shanghai Municipal Police (SMP) Specials with the rank of Inspector in 1926.
Document 10: Pugil stick: A pugil stick is a heavily padded pole-like training weapon used since the early 1940s by military personnel in training for rifle and bayonet combat. The pugil stick is similar to a quarterstaff or Japanese "bo", and may be marked to indicate which end represents the bayonet and which the rifle butt. Dr. Armond H. Seidler (1919-2017) of the University of New Mexico invented the Pugil Stick training method during World War II. It was initially adopted by the United States Marine Corps, but was later included in United States Army combat training as well. Dr. Seidler received an award from the Marine Corps for his invention.
Document 11: Eric Sykes: Eric Sykes, CBE (4 May 1923 – 4 July 2012) was an English radio, stage, television and film writer, comedian, actor, and director whose performing career spanned more than 50 years. He frequently wrote for and/or performed with many other leading comedy performers and writers of the period, including Tony Hancock, Spike Milligan, Tommy Cooper, Peter Sellers, John Antrobus, and Johnny Speight. Sykes first came to prominence through his many radio credits as a writer and actor in the 1950s, most notably through his collaboration on "The Goon Show" scripts. He became a TV star in his own right in the early 1960s when he appeared with Hattie Jacques in several popular BBC comedy television series.
Document 12: Mick Ranger: Mick Ranger is an Essex, UK based firearms dealer. He previously sold Michael Ryan the Chinese "Type 56" copy of AK-47 rifle that he used in 1987 to kill eight people during the Hungerford massacre.
Document 13: William E. Fairbairn: William Ewart Fairbairn ( ; 28 February 1885 – 20 June 1960) was a British Royal Marine and police officer. He developed hand-to-hand combat methods for the Shanghai Police during the interwar period, as well as for the allied special forces during World War II. He created his own fighting system known as Defendu. Notably, this included innovative pistol shooting techniques and the development of the Fairbairn-Sykes Fighting Knife.
Document 14: Ernest Emerson: Ernest R. Emerson (born March 7, 1955) is an American custom knifemaker, martial artist, and edged-weapons expert. Originally an engineer and machinist in the aerospace industry, Emerson became a knifemaker by producing knives for a martial arts class and making art knives early in his knifemaking career. In the 1980s he became better known for his combat knives and popularizing a style of knife known as the Tactical-folder.
Document 15: Walter Walsh: Colonel Walter Rudolph Walsh (May 4, 1907 – April 29, 2014) was an FBI agent, USMC shooting instructor and Olympic shooter. Walsh joined the FBI in 1934, serving during the Public enemy era, and was involved in several high-profile FBI cases, including the capture of Arthur Barker and the killing of Al Brady. He served in the Pacific theatre during World War II with the Marine Corps and, after a brief return to the FBI, served as a shooting instructor with the Marine Corps until his retirement in the 1970s.
ground_truth: Fairbairn-Sykes Fighting Knife