Scotland has even stricter rules about "coats of arms" than apply in England and Wales. There is no such thing as a "family crest" but members of clans are allowed to wear the Chief's crest i.e. the figure, object etc which is displayed on top of the helmet in his "coat of arms" surrounded by a buckled belt. In some cases the motto from the "coat of arms" is used as the clan motto. In other cases there is a different motto or slogan (war cry) usually displayed on the background of the belt. The resulting badge can be worn on the bonnet or as a lapel badge. These days it's quite common to find it on the sgian dhu in the stocking top.
Stand fast is the motto of Clan Grant - hence Grant's Standfast whisky!