Quote:
Originally Posted by
billsayers 
It is the authentic Burberry Prorsum label. The "Prorsum" is listed on the flag the knight is carrying.
The Prorsum flag has always been the signature of the charging knight logo. See vintage label below, clearly before Prorsum was a diffusion line:

"Prorsum" simply means "forward" in Latin. First developed in 1901, their charging knight logo was used to represent how the brand continues to advance (though its original intention was to be used as a representation of their advancements in garment technology: see their jackets being used in WW1, the Arctic Circle, etc).
Today, "Prorsum" is used as a device to demonstrate a line that is
fashion forward. It is the more cutting edge and fashion sensitive offering. This logo might belong to an older Prorsum garment, but as hrb stated, their most recent garments clearly state "Prorsum" below Burberry on the tags (where London, Golf and Brit stand on those diffusions, respectively).