This internal code is also occasionally omitted based on reports from Canon owners. In this case, "F" stands for Fukushima which was the main Canon SLR factory for about 20 years from the early 70s until The factory code is rarely omitted, if ever. Since Canon's SLR lens factory is in Utsonomiya, you might see a date code starting with "UG" for a lens manufactured infor example.
With either the lens' serial number or date code, that question can be answered. The Canon lens date code in the sample picture indicates that this Canon EF. Starting about many went to a 10 digit serial number which should contain a date code. Some "L" lenses like the EF mm have. The story behind Canon's L-series lens range – from the first lens to use fluorite in This timeline reveals Canon's ongoing pursuit for the perfect lens for.