I think it might be helpful for people trying to decode Jackson Import serial numbers if a centralized serial number / Country of Origin FAQ could be put together. I will start with this and if others with more knowledge (or corrections if need be) will post contributions I will edit this first post:


Jackson Import Bolt-on serial number guide:

6 Digit Serials
Starts w/ | Type of Jackson Guitar
0-5 | Professional (MIJ) [or No Series (MIJ) for 1995], first digit denotes year (0=1990, 5=1995) 
6 | 1996 No Series (MIJ)
90-95 | Fusion (MIJ), first two digits denotes year (90=1990, 95=1994) 
96 | 1996 No Series MIJ before switch to 7 digit serial 


7 Digit Serials
Starts w/ | Type of Jackson Guitar
1 | Performer (MIK) 
94 | 1994 MIJ Concept guitars, first two digits denotes year (only made in 1994) 
9 | 1996+ MIJ (all MIJ series, even JS MIJ), started with 96xxxxx and went up sequentially (97,98, etc) 


8 Digit Serials
Starts w/ | Type of Jackson Guitar
00-04 | JS (MII), X (MII) or very early JS30xx (MII) [2004 only], first two digits denotes year (00=2000, 04=2004) 
6 | JS (MIT), probably the first digit denotes year (6=1996) 
96-99 | JS (MII) or X (MII) first two digits denotes year (96=1996, 99=1999) 


9 (or 10) Digit Serials
Starts w/ | Type of Jackson Guitar 
2 | JS30xx (MII), first four digits denotes year, 10th digit added at start of 2008