I was looking at pictures of Mark IV tanks near Brie in March 1918 when I wondered at which date for the front horn, white-red-white stripes were introduced. Reading this discussion (http://landships.activeboard.com/t55953613/introduction-of-horn-stripes/), I now know that these have been introduced in early May 1918, so definately after the actions near Brie. However, the shown document dated 14th March 1918 already describes the application of the stripes on the cab roof. I now wonder if someone knows a picture which shows a Mark IV tank with the stripes on the cab roof, but not on the front horns or the rear, spaced armour. Would this be how the tanks near Brie looked like?
The 'Recognition markings' of 'white/red/white' was only decided on after a series of trials of different types. At Fricourt on 28 February 1918 a series of markings were viewed from aeroplanes, these were a. A white square on the 'cab'. b. An ordinary aeroplane marking on the 'cab' (RFC roundel). c. A white square with black centre on the 'cab'. It was considered that the white square with a black centre was the most conspicuous, but there was not much between them and they all appeared small to the pilots and observers. This did not result in a final decision and some more trials were undertaken with the results published in a letter dated 6th March, 1918, see attached, this resulted in the 'white/red/white being used.