A 99 Flake can refer to an ice cream cone with a Cadbury Flake inserted in it; a specially produced Flake bar for this purpose; or a wrapped ice cream cone product marketed by Cadbury. It was originally designed to be a cuboid, and fit into a wafer. It was later adapted for a cone.
99 ice cream 
A 99 Flake ice cream, or more commonly a 99, is an ice cream cone, usually made with soft serve ice cream, into which a Flake bar has been inserted, typically at an acute angle to the cone. The ice cream is usually vanilla flavoured. They are traditionally sold by ice cream vans and parlours. Variations include a 99 with two flakes - often referred to as a double 99 or "bunny's ears" - and a 99 with strawberry or raspberry topping sauce, sometimes known as Monkey's Blood.
There are many references to 99s in British pop culture. The pop-electronica duo The KLF used ice-cream van iconography and included the phrase "Make mine a 99" in their 1991 single version of "Justified and Ancient".
Cadbury 99 Flake bar 
The Flake chocolate bar itself was first developed in 1920. An employee of Cadbury's noted that when the excess from the moulds used to create other chocolate bars was drained off, it fell off in a stream and created folded chocolate with flaking properties. In 1930, Cadbury started producing a smaller version of the standard Flake bar especially for ice cream cones. These were marketed under the name 99 Flake and sold loose in boxes rather than individually wrapped like the traditional Flake.
The origins of the name are uncertain. One claim is that the '99' was coined in Portobello, Scotland, in 1922, by the Arcari family, Rudi Arcari's father Stephen came up with the idea not long after opening the shop in 1922. He would break a large 'Flake" in half and stick it in an ice cream. A Cadbury's rep took this idea to his company. The rep asked Arcari what he called it, and he gave it the name 99 simply because the shop was sited at 99 Portobello High Street. The idea spread locally, then further afield.
Another possibility, generally discounted, is that it was named by Italian ice-cream sellers (many of whom hailed from mountainous areas in the Veneto, Trentino, Bellunese and Friuli) in honour of the final wave of conscripts from the First World War, born in 1899 and referred to as "i Ragazzi del 99" - the Boys of '99. They were held in such high esteem that some streets in Italy were named in honour of them. The chocolate flake may have reminded them of the Alpine Regiment's hat, with a long dark feather cocked at an angle.
The Cadbury's website says that the reason behind the Flake being called a 99 has been "lost in the mists of time" although it also repeats an article from an old Cadbury works paper, which states the name came from the guard of the Italian king which consisted of 99 men and "subsequently anything really special or first class was known as 99."
- "My grandad created the '99' cone in Portobello". The Scotsman. 18 January 2006. Retrieved 15 February 2012.
- Oliver Thring (24 August 2010). "Consider the 99 Flake". The Guardian. Retrieved 15 November 2010.
- "World's most disgusting ice cream". The Metro. 9 April 2008. Archived from the original on 10 October 2010. Retrieved 15 November 2010.
- "Corporate history of the product". Cadbury. Archived from the original on 2006-08-22. Retrieved 2011-04-17.
- Cadbury FAQ on names of products, Cadbury