Original decal on a 1950 Norman:
Now I have to apologize that I don't have a better photo of this one, but the little silvery rectangle on the seat tube of this 1951 Raleigh Lenton Sports is the 531 decal. This one indicates the bike has straight gauge tubing.
My 1948 Raleigh Record Ace has a similar tiny little decal, also rather beat, indicating butted tubing. It is like the one on the Norman, but much smaller.