Usually, the Cadency mark, the Martlet in the first quarter, signifies a 4th son but apparently he was the 1st son..so would have had a Label as a cadency mark ??
I can´t find any mention of him taking part on the campaign or being at Bannockburn, he was probably busy with the defences of Carlisle at the time but I reckon he would at least have sent a contingent of Soldiers for the Invasion.
Wether he did or didn´t send troops or was in fact present on the campaign, the addition of his banner adds a bit more colour.
