In the mission Flashpoint, Simon "Ghost" Riley is wearing his "Classic Ghost" outfit yet in the first ever Modern Warfare reboot game and Warzone it is canon that he wears a completely different mask and uniform.
Several times Ghost is referred to as LT or Lootenant.
The British army doesn't use 'LT' and the correct pronounciation of the rank of Lieutenant in the UK is 'Leftenant.'
At a push the NCO's could refer to him as 'Rupert' the British Army's over rank reference to an officer.
The trackers have red lights on them, which makes them obvious for anyone looking to see if a tracker is planted.