Sheldon is the caretaker of the Retro-Raleighs website - _not_ the originator of this web site. In fact, the information page on dating your raleigh bicycle on his web site has at least 3 errors, which i just mentioned to him in an email a few minutes ago.
The fortnight theory is an attractive theory, but this jpeg document appears to be original documentation - possibly from a raleigh dealer. I'm going to check all my frames tonight to see if they are consistent with this numbering scheme. I will also see if I can hunt down the ebay auction where it came from.
I'll lay down the gauntlet to the CR / Raleigh crowd : If you think this fact sheet is in error, then email me with your bike, your serial number (note: this is the 1974-onward numbering scheme), and your belief in what year is your bike. I'm betting that NOBODY has a bike with a "C" or "F" fortnight, for example.
- Don Gillies
San Diego, CA