#1 is the usual definition of perfect pitch, and is the most useful. I have heard #2 and #3 referred to as "pitch memory". There is also a rare #0, which is the ability to identify pitches that are out of tune by a small number of cents. This is the least useful type of perfect pitch, and can render people unable to truly enjoy music. I know a musician who is like that. To him, everyone in the band is out of tune all the time.