"Snowflakes" is really a great descriptive word for these. Really brilliant. Going forward, I plan to use that term routinely in describing my autographed T206s.
For instance, I just received this Bridwell in the mail today. Technically it is a duplicate for me because I already own this T206 pose autographed by Bridwell. But there are plenty of differences between the two -- principally the inclusion of the specific date he signed this one in 1967, not to mention the different ink and different SC series. Hard to consider these guys dupes. Just like snowflakes.....
The one I got today:
The one I got back in 2007: