Italy took part in the Spanish civil war, fought between 1936 and 1939, with a large number of troops. Though documentation is quite poor and hard to find, I know that the Italian vehicles had some special plates: they were made of metal, front plates were rectangular with all the characters on one line, while rear plates had still a rectangular shape, but more "squared" and the characters were placed in two lines. The background was light blue and all the characters and the border were usually yellow, though sometimes were painted in black. The following codes were certainly in use:
You can see below some pictures of the first three plates and you can also find the full picture of the plate with the ATV code in the old photo gallery (picture number 23). On the contrary, I haven't got yet any picture of plates with CTV, but itsexistence is proved by a letter written by a man who was in Spain at that time and names it: "Our vehicles had plates with A.T.V., then B.S. and last C.T.V.".
Beside these codes, there are two more, but I'm not sure about their use:
Pictures 1 and 2: Base Siviglia (rear and front)
Pictures 3 and 4: Divisione Volontari del Littorio (motorcycle and autovehicle)
Picture 5: Artiglieria Truppe Volontarie
Picture 6: Milizia Nazionale della Strada
Some special plates of the Milizia Nazionale della Strada (Street Army) were also issued during the Spanish war: they were exectly like the normal plates of the Army used in Italy during the same years, but had the colours used on the plates for Spain, yellow characters on light blue background (the image number 6 is a drawing of such plate and not a picture).
On the plates used in Spain, there is also a little mistery and this is about the plates of the vehicles of the Italian Red Cross used there. In a picture (click here to see it, though it's very small and unclear) there's an ambulance with the rear plate CRI 29068 in one single line. But such a high number hasn't been reached yet today!
Immediately after the civil war all foreign vehicles that were handed over to the Spanish Army by the Germans or Italians had their original plates replaced with Spanish Army ones with the letters ET (Ejercito de Tierra).
I want to thank very much Ernesto Vitetti for all the pictures in this page and for a lot of details about these plates. Moreover I also want to thank Stirling D. Lowery, Marcello Taverna, Roberto Pola, Guglielmo Evangelista and Giancarlo Raposo for the help they gave me to understand better this subject.