The information presented on this website was slowly developed over the last thirty years and has grown, like a city, in several different directions over time. It started as a way for me to keep track of basic information on passenger plate numbers, all in one small notebook (before the computer era). Therefore, to keep the summarized data as concise as possible, early on, I developed a standardized format to list the various parameters of information when it applied to multi-year baseplates. An example of that format, and how to "read" it, appears below. As research progressed, I added truck plates, motorcycle plates, county codes, color schemes, sizes, pre-state plates, and more. The result is what you see today on this site. Updates are still being made weekly!
When it comes to the actual plate numbers listed, all are numbers that have actually been seen on license plates, unless noted that they are inferred from registration records, statistics, or some other source. The only exceptions are as follows: 1.) Low numbers, such as 1, 100 or 1000, etc. are listed as such if it is reasonably known that it was the lowest number issued, even if that plate hasn't been spotted. 2.) Ranges of numbers where a state has issued serial formats by county and/or weight class; we can't record highs and lows of all 105 Kansas counties, so we express an expected range of possible numbers in the system. 3.) Sequencing in predictable systems, such as Michigan's 1979-83 base where numbers began at BBB-000 and ended at ZZZ-999.
We used to have a key to codes and abbreviations on this site, but I have attempted to remove as many of these cryptic 1-, 2- or 3-letter abbreviations as possible, making a key hopefully unnecessary. Some vestiges of my old system remain: An * after a number means that the number is higher than registration figures for that year and type (and *t means the same thing for passenger figures unless trucks are included). In other words, the number is "too" high. However, this is common especially in states with multiple issuing offices, each of which had to be stocked with a sufficient quantity of plates to get through the year. The results? Number "inflation", and possible leftover unissued plates with lower or higher numbers. No attempt has been made to distinguish issued numbers from unissued ones. If a plate was produced, we'd want to collect it whether it was issued or not!
Registration figures, unless noted otherwise, are from the U.S. Department of Commerce (1901-55 passenger, truck and total), U.S. Department of Transportation (1956-75, passenger only), and Transport Canada (1903-73, total only). Alaska and Hawaii figures start in 1959. When figures become available from a state or provincial source directly, these are considered to be more accurate.
GUIDE TO PRESENTATION OF MULTI-YEAR BASE DATA Example: Alaska 1982-98 Flag Base.