In cases where generic non model specific plates are used the 4 digit number is just the consecutive number of that plate which could have made it on possibly 10 different models.
- JEM plates are 6 digit and the first 2 digits is the production year while the last 4 is the consecutive number JEM built from inception. Except for the very first batch of 90' UV plates that began 00, UV plates are also dated by the first 2 numbers. A Universe plate 912787 would denote a production year of 91 and the 2787th Universe built.
9=October, .=November, X=December) 4th and 5th character is the day of production (01 to 31) Although guitars already had serials from 1975, between 19 they used a 6 character serial on pickups: 1st character is a production code (1,2,3, etc., maybe related to different production location) 2nd character indicates the year of production (7=1977, 0=1980, 1=1981, etc.) 3rd and 4th character indicates the month of production (01=January, ...
12=December) 5th and 6th character is the day of production (01 to 31) , This old style serial number will either be on the neck plate or impressed into the back of the headstock.
Post 11/2011 they changed to alpha, 4 numbers, alpha, the first letter being the month, A for January, the last being the year, B for 2011, C for 2012, etc. - The Guitar Dater Project will decode W, S, I and who knows what other prefixes [factory codes].
I do not know how accurate the system is but the few I've run have worked just fine. Plate serial numbers have nothing to do with headstock serial numbers.
- Guitars built in Japan between these years will have a serial number beginning with F followed by 6 numbers.An Ibanez serial number can tell you two things, year of manufacture and factory [or country] of manufacture.There is no master list to correlate to a model number, these are consecutive serialized numbers only.- Under the old numbering scheme 1997 would show duplicate numbers to 1987 so the serial number was changed to the F and 7 digits, now the first 2 denoting year of production. The last 5 numbers will be the consecutive number denoting production count for the year with the caveat that each month will start at predetermined intervals of 3000 or 5000, etc. With production year beginning in November - 00000 - Shown as F for Fujigen in the examples above, other factories used that mainly produced the budget models were C for Cort [Korea], S for Samick [Korea], W for World [Korea], and guitars are also built in I Indonesia, China, and who knows where else.
These serial numbers are usually quite different from the MIJ numbers, have many extra digits because of the enormous volume of guitars produced, and I am not familiar enough with any of them to tell you how to figure out the dating.- Cort serial numbers are denoted with a C prefix followed by either 7 or 8 digits.