Cycles Peugeot in the mid-1970s was manufacturing and exporting a large volume of bicycles. It had two manufacturing facilities. This was no doubt a challenge to manage.

Up to 1976, the frame number and serial number were the same thing. The frame number stamped into the frame of the bicycle or onto an aluminum plate and also served as of the bicycle’s serial number. This number, as best as can be determined, did not have date encoded information.

In 1976, Cycle Peugeot introduce a new system to help manage and identify all of the individual bicycles it produced.

The new system had two components: the frame number on the bicycle frame and a serial number taped to the frame. The frame number and serial number where now separated into two distinct pieces.

In addition, the frame number now had a date code encoded into the first characters of the frame number. Also some of the frame numbers had a factory code prefix letter. In 1980s, this factory code prefix became more standardized and was stamped in almost all the frame numbers.

The frame numbers were stamped into the dropout, or bottom bracket shell, or onto an aluminum label that was riveted to the frame.

The aluminum label frame numbers did not include a factory code letter. The aluminum labels were discontinued in 1978.

The second component took the form of a white labels that was taped with clear adhesive to the bottom bracket. Typed on the white label was the bicycle serial number (not a frame number), a model designation and a frame size in centimeters. I do not know if the white labels were put on to all of the bicycles produced.

Sadly, the adhesive tape did not last forever and most of the labels on the bottom bracket have not survived. Later, the white labels were affixed to the chain stay and these have lasted a little better.