The No.4 rifle had four different sized buttstocks available. Each length increases by 1/2". They are; B-Bantam, S-Short, N-Normal and L-Long. The marking is just forward of the buttplate on the heel, (top), of the buttstock. Bantam stocks were only made in Canadaicon as far as I know. There were no XL-Extra Long buttstocks made for the No.4 rifle.