I noticed that listing only goes up through 2006, so here's some additional information that will help to ID the year going forward: Some time during 2008 PRS started using a "08" instead of an "8" on the serial numbers.
For example, I just got in my first PRS in about 4 years - a KL1812.
1991 -- PRS stopped offering real abalone shell as the inlay material on the fingerboard.
They went to a high quality, less expensive, but real mother of pearl.
This is followed by the sequential number for that particular model.