Port Authority (Capitaneria di Porto)

Plates of Port Authority have never changed their format, but they changed the look. The plate shown on the bigger picture on the left with CP on the first line and the numbers in the second, was used from 1927 (?) until 1982. In that year the new plates with all characters on one line shown in the second picture was introduced and used until 1992. In 1992 a little green star was added on the plates, like for the plates of the Army. Last, in 2000 a sticker with the print "GUARDIA COSTIERA" (coastguard) on bottom was added. Due to the low number of vehicles, letters have never been used and the numbers are assigned to each kind of vehicle according to the following table:

Trailers were introduced in the 1990s, so their plate have always been on a single line, and they have a red R as you can also see in the table above. Also for these plates the label "GUARDIA COSTIERA" was introduced in 2002.
Motorcycles have always had the same plate that you can see in the picture below, even if the letters CP usually were placed in the center and not on the left side.

I want to thank very much Marcello Taverna for all the pictures shown below.

1927 - 1982

1982 - 1992 1992 - 2000

2000 - Today

Motorcycle