In 1901 the Newcomb College Pottery program began a new registration code scheme for tracking production and sales. Unfortunately, none of the original documents related to those codes have been discovered. Regardless, by matching sales data with other records researchers were able to reconstruct the meaning of those codes.

Beginning in 1901, a sequence beginning with letters and numbers began. The first was A-1, then A-2, then A-3, until A-99. The letter then incremented to B, and the numbers began again with 1. So the next pottery was marked B-1, B-2, B-3, until B-99. Then they began again with C-1.

By 1903 they had exhausted all of the letters and reached Z-99. In order to continue tracking their work, they doubled each letter. So directly after Z-99 came AA-1, and then AA-2, AA-3, and so on. After AA-99 they continued with BB-1.

The short-sightedness of this system became apparent in just 1 year. In 1904 they reached ZZ-99 and the system again was full and required adjustment. It was then that the final system was put into place. They started again with AB-1, AB-2, AB-3, and so on, incrementing to AC, AD, AE, etc when required. After AZ-99, they simply incremented the first letter to BA-1, BA-2, etc.

It is important to note that in the final numbering system sequence there are no double letters used, such as GG or XX, because those had already been used 1903 and 1904.

Below is a quick reference chart that indicates the range of prefix letters used in each particular year. Also, the indicated number of pieces likely produced in that year is listed beside them.