If follows there is a third letter E, it stands for Electric.
Exceptions: Some high-end models and lap steels from 1939-1940 have been added the letter A, to the prefixes D, E or F.
Factory Order Numbers (FON) with a letter from 1935 to 1941.
FON consists a batch number of usually four digits, followed by a one letter (sometimes prefixed by a space) followed by one or two digits (ranking).
Even after the closing of the factory in Kalamazoo in 1984, this process was continued until 1989 in Nashville.
In 2005 the system was upgraded to first digit at the end of the batch number was inserted.
Factory Order numbers with a letter from 1952 to 1961.
Where to find the serial number The serial number is stamped or punched on the back of the headstock.
The batch number, the first four digits of the FON, followed by a one or two-digit number. The first digit of the serial number is the last digit of the year.
If the stamped number consists 5 digits, there is a space between the first and second digit (a separation between the last digit of the year and the actual serial number).
The three intermediate digits, the day of that year. After opening of the new factory in Nashville, in the sequence numbers were also included the production site.
001 to 499 appeared on the instruments built in Kalamazoo, 500 to 999 built in Nashville.