Ibanez serial number system is fairly easy
If the guitar was made before 1975 it does not have a serial number it can only be dated by looking at the model and estimating the year. Usually the better copy models are 1973-1974 or early 1975
Before 1987 you can use the following for most Electric Guitars
EXAMPLE C760276 this is March 1976 the 276pc made that month. Not the 276 specific model. The factory does not date a model they just start at 1 and keep going for all the production.
The first letter is for the Month so A is January, B is Feb., C is March and so on. The next two numbers are the Year 76 is 1976, 78 would be 1978. The next 4 numbers are the production number that month they only produced less than 9999 pieces each month.
Post 1987 models
This is a little harder but you can use the following EXAMPLE F700001 The letter is now the Factory designation. The first Number is the year the next 5 numbers are the production number of the piece for the year. so the above guitar was made in 1987 and is the first one made that year. There is no easy way to figure out the month.
Yes it came around that in 1997 that serial numbers would repeat so it was changed to CE F than the Year and 5 numbers for the production run of that year.
Acoustics Are a little harder but usually start with the year and than the month 7502001 is February 1975