History of vehicle registration plates of the Philippines

Philippine vehicle registration plates have a long history. The earliest license plates were introduced around 1912 with the introduction of Legislative Act No. 2159.
In this article, "L" stands for a letter in 1974–1980 and 1981 series plates, "X" stands for an alphanumeric symbol (in 1974–1980 license plates), "P" stands for a prefix (in 1933–1980 license plates), and "D" stands for a number (in all license plates).
Specifications.
Early license plates.
Most early license plates just showed the serial number, most likely a 4 to 5-digit number and a small box on the left of the serial number which displays the 2-digit year mark, which is written downwards. This continued until 1932.
e.g. 31 44789, 31 stands for the year 1931
1933 series.
With the Revised Motor Vehicle Law (Act No. 3992) introduced in 1933, second-generation Philippine license plates were introduced; they can be in the format of "A-B" or "P-B", where A is an area code number (used until 1960), P is a vehicle classification prefix, and B is a 3 to 6-digit number. Sometimes single-letter suffixes were used.
Hyphens were used in separating the numbers; this was later replaced by asterisks in 1938. On the bottom of the license plate are the 2-digit year mark, the place the car is registered, and the word "P.I.", in that order (e.g. "36 MANILA P.I.", 36 stands for 1936). In 1938 the "P.I." was dropped, the place name and the year mark were simply displayed (e.g. MANILA 60, 60 stands for 1960). Prefixes were common in license plates starting in 1938. Sometimes prefixes stand for place names (e.g. "PS" stands for Pasay).
1970 series.
In 1970, Philippine vehicle license plates adapted a numbering format similar to Japanese license plates. It can be in a format of "DD-DD", (from 0–0 to 99–99, sometimes 00 to 09 are used) with single or double-letter suffixes. Most vehicle category prefixes are on the lower-left of the plate. For government vehicles, "RP" is displayed before the number. Year stickers were introduced in 1973.
1974 series.
A new license plate format was introduced for the year 1974. The format is "L DDD", "DDD L", "XX DDD" or "DDD XX", with the vehicle classification at the lower-left corner of the plate, followed by the place name (which was changed to "PILIPINAS" in 1977), and the 2-digit year marker. The initial typeface resembles the 1970 series plates. (e.g. G 582, 159 F, FE 358, 576 NK)
1981 series.
In 1981, the vehicle registration plate system has been revised again, taking the format of LLL-DDD. Color-coded year stickers appear for the first time in 1982, based on the license plate's color scheme (notable exceptions are in 1983, 1984, 1986, 1988, 1989, 1990 and 1993). Stickers for vehicle classification appeared in the same year. The byline at the bottom of the plate was displayed as "PILIPINAS".
2014 series.
In January 2013, Land Transportation Office ventures the plate standardization project with safety features that will have bar codes, and 1981 series are now unavailable. LTO will issue new format for light motor vehicles LLL-DDDD and for motorcycles LL-DDDDD.
Lists of prefixes.
In 1938, prefixes were common on license plates. Prefixes can be combined (e.g. RPTR, which denotes a government-owned trailer). Most of the prefixes took the form of stickers starting in 1981.
Place prefixes.
1981 series.
I & O are not used to avoid confusion with the numbers 1 & 0, used only
for private motorcycles.<br>
Q is a special letter and is not used on regular plate circulation or used only
for motorcycle-tricycle for hire.<br>
But these Letters are now used as middle or last letters, or both for Manila Plates since 2009.<br>
O & Q Was Also used For Provincial Plates In Central Visayas In The Middle Of 2010. (e.g. YJO-248, YJQ-768)<br>
On 2014, From XAI-ZQZ For Manila Plates Was Been Skipped.
2014 Series.
From April 13, 2014 to June 30, 2016, the plate number letters are all the same throughout the Philippines in a series and combination, since the region where it is registered is now displayed in the new license plates at the bottom part.
2018 Series.
Registered vehicles from July 1, 2016 and beyond will have the same alphabetical designation as in the 1981 license plate series.