Maryland mystery license plate

Rick Kretschmer's License Plate Archives 

Maryland mystery license plate

A Pictorial History of Maryland License Plates

Unidentified plate types, 1920 to 1958


On this page I show and tell what I know about various Maryland "mystery" plate types from before my time, 1920 to 1958. 

Latest noteworthy updates to this page
  • January 24, 2019  –  Added a photo of a 1922 "200" series plate. 
  • September 7, 2016  –  Added photo and discussion of a 1948 base plate with the letters P.T. in place of the expiration year "48". 


There are some Maryland license plate types that I just don't know much, if anything, about.  Invariably, these Maryland "mystery" plates are from before my time, when I could have observed them in actual use.  Also, there seems to be little or no information available about these plates, and what information might be available is either incomplete, contradictory, or speculative in nature. 

I will report what I do know, do some of my own speculation, and provide photos when possible about these unknown plate types.  If you can shed any light on any of these mysteries (with facts, not more speculation), or can provide a plate or a photo of a plate that I'm missing, please send me an e-mail.  There's a link to my e-mail address at the bottom of every page. 

"100 and "200" series plates

1921 passenger 1922 passenger 1923 passenger

Years known:  1920 through 1923.  (As far as I know, there's nothing special about these from 1924 on.) 

Maryland car passenger plate numbers began at 20-000 in 1920, and at 30-000 starting in 1921.  It's been reported that there were approximately 84,000 passenger car registrations in Maryland in 1920, which would mean that passenger car plate numbers went beyond 99-999 for the first time.  It would be expected that plate numbers continued into the 100-000 series, and indeed, such plates do exist.  However, I have a photo of a 1920 Maryland plate with number 200215 (without a dash separator), with nothing to identify the plate type or vehicle type.  I have similar photos of 1921 Maryland plate number 200-628 and 1923 Maryland plate number 201-150.  In all four of these years, there's a significant gap between the highest expected passenger car plate number and these 200-series plates. 

I've seen one explanation for these 200-series plates that seems plausible to me, though I can't remember where I saw it.  Prior to 1924, Maryland and the District of Columbia did not have a reciprocity agreement, meaning that a motorist from one jurisdiction who wanted to drive in the other had to register his vehicle in both places.  Many D.C. residents therefore displayed both D.C and Maryland plates on their vehicles.  Anyway, the explanation I heard was that beginning in 1920, Maryland issued 200-series plates to D.C motorists (and possibly also other motorists from adjoining states) who wanted to drive in Maryland.  In December 1923, Maryland and D.C. agreed to recognize each other's license plates as valid, and the need to register a vehicle in both jurisdictions went away.  Maryland apparently exceeded 200,000 passenger car registrations from their own residents for the first time in 1924, and so the 200-series plates from 1924 and beyond have no special significance. 

However, another report indicates that plates issued to non-residents were in the 100-000 series, and plates for Maryland residents jumped from 99-999 to 200-000 and above.  Based on the numbers of plates issued in both the "100" and "200" series, I don't believe this is correct.  Far more 100-series plates were issued than were 200-series.  I would expect that the numbers of new car owners in Maryland would be much greater than the numbers of new cars in D.C. who wished to drive in Maryland. 

Plate numbers observed
  • 1920:  200215
  • 1921:  107-891, 200-628
  • 1922:  104-657, 122-405, 125-738, 218-476
  • 1923:  173-173, 201-150, 233-965

"F" series plates

1936 "F" series 1949 "F" series
(1936:  Tyler plate)

Years known:  1935 through 1951

I had never seen or heard of this plate type, with an "F" serial prefix or suffix, until I saw a pair of 1940 expiration plates on eBay (which I unfortunately did not win).  One source indicates "F" plates were for funeral limousines.  I obtained the 1949 plate shown above along with several "FH" prefix plates from various years in the 1940s; "FH" plates are reported to be "funeral hearse" plates.  I was told that the original registrant of both the "F" and "FH" plates was R. Madison Mitchell, a Havre de Grace undertaker, thus lending credibility to the report that "F" plates were used on funeral vehicles other than hearses.  My hunch is that they were used on all kinds of non-hearse funeral vehicles, including flower cars. 

Plate numbers observed
  • 1935:  8-109F
  • 1936:  F9-730
  • 1940:  F28-509
  • 1948 base:  F28-092, F28-262

"SR" series truck tractor and trailer plates

1956 "SR" trailer 1957 "SR" trailer 1958 "SR" truck tractor
1956 and 1957 "SR" trailers; 1958 "SR" truck tractor 

Years known:  1942 through 1958

These mysterious "SR" plates were issued to truck tractors (that, is the cab part of a tractor-trailer), and to trailers.  I presume that "SR" trailers were actually semi-trailers pulled by "SR" truck tractors.  I have no idea what "SR" stood for or meant.  I've seen various explanations that it stood for "shuttle relay" or "special rate" or "state roads".  But even if any of these are correct, there still is no explanation for what these terms actually meant, or what qualified a truck tractor or trailer for these "SR" plates rather than regular tractor or trailer plates. 

1942 and 1945 SR trailer base plates looked like regular trailer plates with a small "T" serial prefix, but also had a stacked "SR" suffix.  1942 and 1945 SR tractor base plates had the same quirks as did regular tractor plates from these years which included the legend Traction across the top of the plate, and the state abbreviation MD, the expiration month and date, and the expiration year stacked horizontally on the left side of the plate.  Again, they had the stacked suffix letters "SR" following the serial number. 

Beginning on the 1948 base plate, the letters "SR" became a serial prefix on the left of the plate for both tractors and trailers.  Tractors had the partial word Trac running vertically down the right side of the plate, while trailers had a small letter "T" as a serial suffix. 

Plate numbers observed (prior to 1954)
  • 1948 base SR tractor:  S/R 7-423
  • 1952 base SR tractor:  S/R 6-790

"P.T." plates

"1948 "P.T." plate
(Willard plate) 

Years known:  1948 through 1951. 

I know next to nothing about this plate type.  I'm told that it's a "private passsenger transportation" plate, although I have no solid evidence of that.  I'm guessing that this term indicated something along the lines of a person accepting payment to drive his fellow employees to and from work.  However, this is all heresay and speculation. 

To the best of my knowledge, the plate shown above is the only such plate known to still exist.  It looks like an ordinary passenger car plate, except for the letters P.T. in place of the expiration year "48" at the bottom center of the plate.  I presume that this plate type was renewed for 1949 through 1951 expirations with metal tabs that were the same color as regular year tabs, but also with the letters P.T.  Otherwise, if regular year tabs were used, it would defeat the purpose of stamping the plate with those letters. 

Plate numbers observed
  • 1948 base:  796-812

"800" and "900" series plates

1948 "800" series 1948 "900" series
("900" series:  Sallmen photo / plate) 

Years known:  1948 through 1951.  (1952 and 1953 "800" series are known to be truck plates.) 

Prior to the 1954 plates, both passenger cars and regular trucks had all-numeric plate numbers.  Beginning with the 1952 plates, most Maryland non-passenger registrations were shifted to expire annually each April 30, while passenger car and motorcycle registrations continued to expire annually on March 31.  Since 1952 expiration plates had the expiration month embossed on the plate, it's easy to see that plate numbers between 30-000 and 799-999 were issued to cars, while plate numbers between 800-000 and 899-999 were assigned to trucks.  I've never seen a 1952 base plate in the 900-000 series, however. 

It seems to be a matter of debate whether truck plates had a distinct serial range prior to the 1952 plates.  Some sources say yes, high serial numbers were also reserved for trucks in earlier years; others say no, and claim to have photographic evidence that shows trucks with pre-1952 plates bearing low serial numbers.  I have not seen any of these photos myself. 

Plate numbers above 799-999 were not issued until the 1948 base.  Pretty much the entire range of "800" and "900" series plates were issued on the 1948 base, but while "800" series plates are known to be truck plates on the 1952 base, no "900" series plates were issued on the 1952 base.  If, in fact, the "800" series was also used for trucks on the 1948 base (which is not certain), that still leaves the mystery of the plates in the "900" series. 

It's been suggested by others that blocks of numbers may have been assigned to various geographic locations within the state.  Of course, it's also entirely possible that prior to 1952, specific but undetermined blocks of numbers were reserved for passenger cars, trucks, and possibly other vehicle types.  Anyway, I suspect that with large numbers of people buying vehicles following World War II, some blocks of numbers were exhausted, and additional numbers were assigned from the previously-unused "800" and "900" series.  It may be that these blocks of numbers were consolidated into just the 30-000 to 799-999 car series and the 800-000 to 899-999 truck series on the 1952 base, allowing for fewer unused gaps at the end of each block of numbers and eliminating the need for the "900" series. 

Plate numbers observed
  • 1948 base:  801-855, 809-310, 814-940, 828-860, 847-406, 850-088, 870-025, 873-948, 875-967, 877-895, 883-298, 890-931, 895-846, 903-800, 923-235, 925-263, 925-457, 944-699, 955-417, 971-337, 973-793, 980-726, 986-069, 994-775, 997-962
  • 1952 base:  801-598, 811-288, 817-112, 822-900, 832-032, 839-702, 839-851, 840-105, 843-302, 846-713, 852-279, 853-571, 873-769, 880-652, 895-642

"C" prefix plates

(no picture available)

Years known:  1952 through 1953

Plates with a small "C" prefix are reported to have been issued on the 1948 and 1952 bases, although I've only seen them on the 1952 base myself.  These have been variously reported to be for commercial vehicles (trucks) or for ambulances and hearses.  These reports sound to me like they're based on speculation rather than verified fact.  If they are truck plates, they would have to be for some specific, unusual type of truck, or else these plates would be vastly more common than the are. 

Since 1954, commercial ambulances, hearses, and other funeral and cemetery vehicles have always used the letter "C" in the serial number, but whether these vehicles were identified this way prior to the 1954 plate is questionable in my mind, because no other class of vehicle used 1954-era letter codes prior to 1954.  On the other hand, maybe "C" plates were for ambulances, while "F" and "FH" plates were for funeral vehicles.  Or, considering that I've only come across "F" and "FH" plates prior to the 1952 base, and "C" plates on the 1952 base, it may be that "C" plates replaced either or both the "F" and "FH" plates.  In any case, it's clear I just don't have a large enough sample, or enough supporting information, from which one can draw any meaningful conclusions. 

Plate numbers observed
  • 1952 base:  C28-389, C28-458, C28-474, C28-488, C28-653

"AE" suffix plates

1957 "AE" suffix

Years known:  1955 through 1957

Between 1954 and 1975, Maryland plates with April 30 expiration dates, and using serial formats with four numbers followed by two letters, were used for vehicle types other than private passenger cars.  In most cases on such plates, the first letter indicated the vehicle class code.  However, "A" is the code for private passenger cars, so we have an apparent contradiction. 

I have found absolutely no information about "AE" plates, and really just don't know what this plate type might have been used for.  However, since "E" is the code for trucks, and in one case, letters "HE" were used for trucks for hire, I'm lead to think that this may be some kind of truck plate, perhaps for a car-truck hybrid kind of vehicle.  Two such vehicle types I can think of are truck-based passenger vehicles, and car-based cargo-carrying vehicles. 

Truck-based passenger vehicles eventually did get their own plate type in 1979:  multi-purpose passenger vehicle, or MPV plates.  Nowadays, MPV plates are issued to all sorts of SUVs and mini-vans.  In 1979, though, it was pretty much just truck-based passenger wagons and passenger vans that received MPV plates.  Vehicles such as the Chevy Suburban, Ford Bronco, and VW Bus.  Possibly in the 1950s, the state issued these "AE" suffix plates to such vehicles. 

Another possibility is car-based cargo-carrying vehicles.  One such type were "sedan delivery" vehicles, which were basically station wagons without side windows or back seats.  They were used much like full-sized Ford and Chevy cargo vans are used today.  Another car-based cargo vehicle type was the car-based pickup truck.  However, the first one of these, the Ford Ranchero, wasn't introduced until the 1957 model year. 

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Page credits

Thanks to those who have directly contributed to the information on this page:  "Tiger" Joe Sallmen and John Willard. 

Sallmen photograph was submitted by and is presumed to be copyrighted by Joe Sallmen, and is used with permission.  Tyler and Willard plates are from the collections of Wayne Tyler and John Willard, respectively. 

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