Vehicle registration plates of Greece

Greek vehicle registration plates are composed of three letters and four digits per plate (e.g. codice_1) printed in black on a white background. The letters represent the district (prefecture) that issues the plates while the numbers range from 1000 to 9999. As of 2004 a blue strip was added on the left showing the country code of Greece (GR) in white text and the Flag of Europe in yellow. Similar plates but of square size with numbers ranging from 1 to 999 are issued for motorcycles which exceed 50 cc in engine size.
With the exception of Athens and Thessaloniki which are represented by just the first letter of the three, all other districts are represented by the first 2 letters. The final one or two letters in the sequence changes in Greek alphabetical order after 8,999 issued plates. For example, Patras plates are codice_2, where ΑΧ represents the Achaia prefecture of which Patras is the capital. When codice_3 is reached the plates turn to codice_4 and this continues until codice_5 is finished. Only letters from the intersection of the Latin and Greek alphabets are used, specifically Α, Β, Ε, Ζ, Η, Ι, Κ, Μ, Ν, Ο, Ρ, Τ, Υ, Χ (in Greek alphabetical order). This is because Greece is a contracting party to the Vienna Convention on Road Traffic, which in Annex 2 requires registration numbers to be displayed in capital Latin characters and Arabic numerals. The rule applies in a similar way in Russia, Ukraine, Belarus, Bosnia and Herzegovina and Bulgaria.
Combinations used for overseas residents are codice_6 (where L = letter and N = number) and are limited. Until 2003, taxis used codice_6; the plate was aligned with the prefecture and the letters were colored red.
History.
1911-1954.
Up until 1954 Greek number plates were quite simple: black numbers on a white background, indicating the serial number shown on the car's license. These started at 1 and advanced to approximately 75-000 when the system was changed. The owner had to provide the plates and specifications were minimal: the size of the plates and numbers, as well as their respective colours. This meant that plates were not very uniform. Taxis had to indicate the initial of the city they were licensed in (e.g. "A" for Athens). In 1954 it was compulsory for all vehicles to change to a new system.
1954-1956.
For just 2 years the system was codice_8, codice_9, codice_6 or codice_11 with black characters on yellow background where L was the initial of the city they were licensed in (e.g. "A" for Athens, "Θ" for Thessaloniki etc.). All these plates display "1953-54" (the initial time period for the change - later revised) in black characters on a white background using a smaller typeface in the top left corner. These plates were compulsorily withdrawn in 1956.
1956-1972.
In 1956 the system was again changed to just numbers codice_12. NNNNNN could be any number from one to six digits starting once again with "1" and ending this time at about "451000", though not all numbers were allocated. Characters were black on white background with a band at the top of both front and rear plates indicating city/district of registration and type of usage (private, commercial etc). Sometime after the early 60s the band on the front plate was abandoned and hence that plate became shorter in height, while the band at the rear became blue. This time it was not compulsory to change plates after 1972 when the newer system arrived. Hence these so-called "six-figure plates" can still occasionally (as of 2018) be spotted on a few old vehicles.
1972–1985.
In 1972, they became lettered and the system was codice_13 while trucks used codice_6. Again, they were black characters on white background but with a new typeface. It was not compulsory to change these plates when the newer system arrived.
1984–2004.
In 1984, the system changed to codice_15 and the first two letters are prefecture letters (with the exception of the biggest prefectures Attica/Athens and Thessaloniki where only the first letter remained the same). Again, it was not compulsory to change to the newer "euro" plates in 2004.
2004 to present.
In September/October 2004 the euroband and international country code (GR) were added to the left and the typeface changed. In all other respects the previous system codice_15 continued with the numbering allocation carrying on as from pre-2004.
Historic Vehicle plates.
Historic vehicle number plates can be issued for vehicles over 30 years old, after they pass the "authenticity" inspection. They came in yellow/blue, white/blue or white/orange depending on the historic vehicle organisation (FILPA or FHVE) and they consist of 4 numbers. 
Prefectures (in Greek alphabetical order).
The first 2 of 3 letters (which are listed below) of a licence plate usually represent the prefecture (nomos) where the car was registered. The almost full list of plates in Greece is below (next to the prefecture / district is its capital or an area within the prefecture that the plates are issued; some prefectures have more than one combination):
Special plates.
Vehicles that belong to public services and armed forces use special license plates with the following letter combinations followed by numbers: 
The following categories are conflicting: The same letter combinations are used for both public services and specific regions:
For truck trailers over 3.5 tonnes without a prime mover:
The letter P followed by a hyphen and 5 or 4 numerals is used.