Box Design Codes
Each Post cereal carton went through a planning phase where design details of the box were chosen. The first step in the design phase appears to have been assignment of a code for each product. The code was sequentially given based on the order in which the boxes were designed. On one of the side flaps at the bottom, each box was stamped with the code that was used throughout the design and production phases to identify the product and the total number of different back panels that would occur for each product. 
A typical box design code is shown here. Each code starts with "P-" followed by a four digit code and then a series of letters. The four digit code starts with 2 that stands for the year 1962, using 2 to designate the year. The following three digits is the next number available for box codes for the year. Apparently Post started with 000 and didn't plan on assigning any box codes past 999, meaning they allowed for 1000 different box designs per year. The letter sequence following the sequential code was a designation of how many different backs the box would have. For example, Post Toasties 18 oz. boxes had two different back panels so the code was AB. Sugar Crisp boxes had three unique back panels and its code was ABC. A box with six back panels like Grape Nuts Flakes 12 oz. shows as ABCDEF and the Post Tens trays, of which there were seven different, was ABCDEFG.
Each box also has a C&C logo with either GENLAM or GENFORD printed above it. C&C stands for "Carton & Container." Retired Post employee and veteran collector, Terry Faulk, explains that in Battle Creek, Michigan, Post had a carton and container plant located across the street from the plant where the boxes were filled. Lamination of paper to cardboard occurred at the carton and container plant. It is not known for certain, but it is likely that GENLAM and GENFORD referred to something associated with the laminating process. As shown in the chart below, three cereals were marked with the GENFORD label—Alpha-Bits, Crispy Critters and Grape Nuts—and the rest were designated GENLAM. Terry provided the postcard shown below with details that only three cereals were processed in Building 20 (buildings marked by number)—Alpha-Bits, Crispy Critters and Grape Nuts. There may be no correlation whatsoever, but it doesn't seem to be much of a stretch to conclude that the GENFORD designation possibly had something to do with those boxes all going to Building 20 for processing.
David Charles is the collector responsible for producing the chart below that shows the codes assigned for the 1962 Post cereal football promotion. The two middle digits of the Top 3 box aren't known. Twelve ounce Post Toasties Top Flap boxes were marked individually with A (panel 2), B (panel 132), C (panel 66) and D (panel 130.) Possibly this was done to prevent confusion with the Flip Out Spout boxes. As documented on the Oat Flakes page, the 15 oz. Oat Flakes boxes were never sold in stores. The sequence number assigned to the OF15 product shows that many boxes were designed after the last football promotion carton released for public consumption (Grape Nuts 16 oz.) and before the OF15 box. Maybe this is a clue that Post was rethinking the release of football cards on the backs of 15 oz. Oat Flakes boxes.
| 1962 Post Cereal Football Box Codes | ||
| Product | Carton & Container Type | Design Code |
| Top 3 10 oz. | GENLAM | P-2xx1ABCDEF |
| Sugar Crisp 9 oz. | GENLAM | P-2772ABC |
| Sugar Crisp 14 oz. | GENLAM | P-2773ABC |
| Sugar Coated Corn Flakes 10 oz. | GENLAM | P-2774ABCD |
| Rice Krinkles 10 oz. | GENLAM | P-2775ABCDEF |
| Raisin Bran 10 oz. | GENLAM | P-2776ABCD |
| Raisin Bran 14 oz. | GENLAM | P-2777ABCD |
| Post Tens | GENLAM | P-2778ABCDEFG |
| Alpha Bits ¾ oz. | GENLAM | P-2779ABCDEF |
| Post Toasties 8 oz. | GENLAM | P-2780ABC |
| Post Toasties 12 oz. Top Flap | GENLAM | P-2781A |
| P-2781 B | ||
| P-2781 C | ||
| P-2781 D | ||
| Post Toasties 12 oz. Flip Out Spout | GENLAM | P-2782ABCD |
| Post Toasties 18 oz. | GENLAM | P-2783AB |
| Bran Flakes 11 oz. | GENLAM | P-2784ABCD |
| Bran Flakes 16 oz. | GENLAM | P-2785ABCD |
| Grape Nuts Flakes 12 oz. | GENLAM | P-2786ABCDEF |
| Grape Nuts Flakes 16 oz. | GENLAM | P-2787ABCD |
| Alpha Bits 8 oz. | GENFORD | P-2788ABCD |
| Alpha Bits 13 oz. | GENFORD | P-2789ABCD |
| Crispy Critters 8 oz. | GENFORD | P-2790ABCD |
| Crispy Critters 13 oz. | GENFORD | P-2791ABCD |
| Oat Flakes 10 oz. | GENLAM | P-2792ABCD |
| Grape Nuts 11 oz. | GENFORD | P-2793AB |
| Grape Nuts 16 oz. | GENFORD | P-2794ABC |
| Treat-Pak | P-2795 | |
| Oat Flakes 15 oz. | GENLAM | P-2881ABCD |
