That is the date of an archived post on discussing Electro 35 serial numbers where a forum member presented a crude Google translation of the date code theory he had found on a Chinese website. The reason I say this is that in late 2017, I have become aware that an unknown Chinese person solved the puzzle, certainly for post 1960 non-SLRs, including TLRs, at least as long ago as August 2006. Together, we solved the YF and other SLR patterns until from late 1968, they again followed the TLR system (the cut-off for our investigations was the introduction of the Contax RTS and the Contax/Yashica mount). Contributor Chris Whelan worked out that the YE rangefinder and Pentamatic SLR also used date codes but the implementation was a little different to the other models. The working out of the date codes and serial number patterns for the TLRs and some of the non-SLRs presented here is entirely my own work. Location of Body Serial Numbers Acknowledgement The Yashica Spares System Theory - the Impact on Serial Numbersĭo These Patterns and Date Codes Exist for Other Format Yashica Models? 7 Digit Numbers - Correlation to Model Release and End Dates