Ibanez did not put serial numbers on their guitars. The only way to date these guitars is to find out what years they were available and then comparing all the minute details like scripts, contours, and inlay variances that only the hardcore vintage gurus know.
These guitars can be dated by their electronics if they are original.
Here is the breakdown courtesy of Ibanez Collectors World.
Until 1977 Maxon used 5 digit serials: 1st character is a production code (1,2,3, etc., maybe related to different production location) 2nd character indicates the year of production (2=1972, 3=1973, etc.) 3rd character indicates the month of production (0=January, 1=February, ...
In a case where a guitar has both the true serial number will always be the headstock number.
Plate numbers usually follow the pattern of the first 2 digits denoting year of production followed by a 4 digit number that denotes consecutive production for that model for that year, or consecutive production number for that particular model from the models inception.;) This page is for dating Ibanez guitars built in Japan only.See the Factories heading a few paragraphs down for little info on guitars produced elsewhere.On typical Ibanez serial numbers the first 2 digits will indicate year, or the first digit will indicate the last digit of the year, but there are also some that indicate no year at all.Because allot of it can be confusing I'll spell out as many model/serial types as I can remember tonight in a fully inconcise and dribble filled rant.A 7 digit number example - C5030567 - translates, 5 = 1995, 03 = 3rd month [March], 0567 = 567th guitar built in March 1995.An 8 digit number example - C03114373 - translates, 03 = 2003, 11 = 11th month [November], 4373 = 4373rd guitar built in November 2003.160225 was a very odd plate number I came across on a Jem.Most that I'm aware of are what I call 250k plates [25****] and current 2003' FP15th's have 260K plates [26****] meaning there have been over 10,000 Jem's made since they deviated from the serial plate numbering.- 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.