## Introduction

The Rolleiflex TLRs had serial numbers from the start of production in 1928. The numbers were sequential although several models received numbers from the same block between 1928 and 1932. The Rolleicords had no body numbers between 1936 and 1938. The official number was the lens number. Rollei began to use coded serial numbers from the late 1970s. The week of production can be read from the number. The TLRs followed in 1987. However a “Special Order” 3.5 № 5205297 equipped with a Xenotar surfaced in 2005. It is said to be from 1980. Perhaps this is an early example of the use of coded serial numbers. It fits the 7 digits structure.

## Rolleiflex GX and later TLRs

The coded serial number has 7 digits, 6036942 for instance. The first digit plus 5 (the key) represents the year of manufacture, in this example 6 + 5 = 11. When the sum is over 10, distract 10. The result is "1". One has to guess the decade and the century! Knowing this number belongs to a black 2.8 GX, the year would be 1991.

The digits placed in the second and third position, (in our example "03") are for factory internal use. They are called the Index.

The digits in 4th and 5th position minus 20 give the calendar week in the year of production. In our example the digits 4 and 5 are “69”. 69 - 20 = 49 so the camera was manufactured in the 49th week of 1991.

The digits 6 and 7 stand for the sequential number of the camera. In our example “42” means the camera was the number 42 manufactured in the 49th week of 1991 with an index of 03. For those who are interested: № 6036942 was seen in auction. It is a 2.8 GX of the ‘Helmut Newton Edition’.