Title rated 0 out of 5 stars, based on 0 ratings(0 ratings)
Book, 1966
Current format, Book, 1966, , No Longer Available.
Book, 1966
Current format, Book, 1966, , No Longer Available. Offered in 0 more formats
Explains how to write and decipher space codes, hidden word codes, and alphabet codes and gives formulas for invisible ink. Includes suggestions for delivering coded messages.
From the community