naming schemes for different widths of shoes and lasts
British Fittings
1, 2, 3, 4, etc.
American System
- A, B, C, D, E, F
- extended:
- AA, AAA, AAAA, etc.
- EE, EEE, EEEE, etc.
Rubber Shoes
In rubber shoes the sizes run the same as in leather footwear, but with a different set of marks indicating widths. The complete list of width marks is: S-slim; N-narrow; M-medium; F-full; FF-extra full; W-wide, WW-extra wide. Many stores stock them only in N, M and F.
— The Shoe and Leather Lexicon, Fourth Edition, 1918