define multiple release years for an album
As I understand it, there is no such capability in iTunes. However, the ID3 tag description on Wikipedia has some information. Basically, what you want is possible, but varies between ID3 tag version.


In ID3 v2.3:

There is a TORY tag for the original release year
There is a TYER tag for the actual release year

In ID3 v2.4:

There is a TDOR tag for original release time
There is a TDRL tag for actual release time



In effect, v2.4 got more specific with the tags (going from year to time), and any half-decent ID3 tag editor should handle either version of the spec just fine. However, iTunes doesn't handle these tags natively.