Several reputable sources mistakenly claim that Kipling's father belonged to the Irish Mavericks featured in Kim. The Mavericks are in fact a fiction, although the colourful regiment, with their reputation for drinking and 'worship' of the regimental flag, is clearly drawn from Kipling's own experience of the British Indian Army.
The imaginary Mavericks are also the subject of Kipling's short story 'The Mutiny of the Mavericks', perhaps contributing to the belief that the regiment actually existed.
The Mavericks are singing a tune popular in the late 19th century, called "The Mulligan Guards". Composed in 1875, it rapidly became a hit throughout Europe and America.