Question: Christopher Robin Milne is the son of an author who held what rank in the British Home Guard?

Context articles: Roo
Christopher Robin Milne
Christopher Robin
When We Were Very Young
Home Guard (United Kingdom)
Hadžiefendić Legion
Northover Projector
A. A. Milne
Ulster Defence Volunteers
Tigger

Roo is a fictional character created in 1926 by A. A. Milne and first featured in the book "Winnie–the–Pooh".
 He is a young kangaroo (known as a joey) and his mother is Kanga.
 Like most other Pooh characters, Roo is based on a stuffed toy animal that belonged to Milne's son, Christopher Robin Milne, though stuffed Roo was lost a long time ago.
Christopher Robin Milne (21 August 1920 – 20 April 1996) was the son of author A. A. Milne.
 As a child, he was the basis of the character Christopher Robin in his father's Winnie-the-Pooh stories and in two books of poems.
Christopher Robin is a character created by A. A. Milne.
 He appears in Milne's popular books of poetry and Winnie-the-Pooh stories and is named after Christopher Robin Milne, the author's son.
 The character has subsequently appeared in Disney cartoons.
When We Were Very Young is a best-selling book of poetry by A. A. Milne.
 It was first published in 1924, and was illustrated by E. H. Shepard.
 Several of the verses were set to music by Harold Fraser-Simson.
 The book begins with an introduction entitled "Just Before We Begin", which, in part, tells readers to imagine for themselves who the narrator is, and that it might be Christopher Robin.
 The 38th poem in the book, "Teddy Bear", that originally appeared in "Punch" magazine in February 1924, was the first appearance of the famous character Winnie-the-Pooh, first named "Mr. Edward Bear" by Christopher Robin Milne.
 In one of the illustrations of "Teddy Bear", Winnie-the-Pooh is shown wearing a shirt which was later colored red when reproduced on a recording produced by Stephen Slesinger.
 This has become his standard appearance in the Disney adaptations.
The Home Guard (initially ""Local Defence Volunteers"" or "LDV") was a defence organisation of the British Army during the Second World War.
 Operational from 1940 until 1944, the Home Guard was composed of 1.5 million local volunteers otherwise ineligible for military service, such as those too young or too old to join the services, or those in reserved occupations–hence the nickname "Dad's Army".
 Their role was to act as a secondary defence force, in case of invasion by the forces of Nazi Germany and their allies.
 They were to try to slow down the advance of the enemy, even by a few hours in order to give the regular troops time to regroup.
 The Home Guard continued to guard the coastal areas of the United Kingdom and other important places such as airfields, factories and explosives stores until late 1944 when they were stood down, and finally disbanded in December 1945.
The Hadžiefendić Legion () or Muslim Legion was a Bosniak self-defence militia and Croatian Home Guard unit based in the predominantly Muslim Tuzla region of the Independent State of Croatia (NDH) during World War II.
 The brigade–sized force was formally a "Volunteer Home Guard Regiment", and was raised in late December 1941 under the command of the former Royal Yugoslav Army reservist Major Muhamed Hadžiefendić, who had been commissioned into the Croatian Home Guard.
 By the end of the year, the Legion had commenced forming battalions in six towns in northeastern Bosnia.
The Projector, 2.5 inch—more commonly known as the Northover Projector—was an "ad hoc" anti-tank weapon used by the British Army and Home Guard during the Second World War.
 With a German invasion of Great Britain seeming likely after the defeat in the Battle of France, most available weaponry was diverted to the regular British Army, leaving the Home Guard short on supplies, particularly anti-tank weaponry.
 The Northover Projector was designed by a Home Guard officer named Robert Harry Northover to act as a makeshift anti-tank weapon, and was put into production in 1940 following a demonstration to the Prime Minister, Winston Churchill.
Alan Alexander Milne ( ; 18 January 1882 – 31 January 1956) was an English author, best known for his books about the teddy bear Winnie-the-Pooh and for various poems.
 Milne was a noted writer, primarily as a playwright, before the huge success of Pooh overshadowed all his previous work.
 Milne served in both World Wars, joining the British Army in World War I, and was a captain of the British Home Guard in World War II.
The Ulster Defence Volunteers (UDV) and later the Ulster Home Guard were a force recruited by the Government of Northern Ireland to perform the role of the Home Guard in Northern Ireland during World War II.
 The UDV was recruited following the formation of the Home Guard in Britain around May 1940.
Tigger is a fictional tiger character originally introduced in A. A. Milne's book "The House at Pooh Corner."
 Like other Pooh characters, Tigger is based on one of Christopher Robin Milne's stuffed toy animals.
 Tigger appears in the Disney cartoon versions of Winnie the Pooh and has also appeared in his own film.