After my first batch of 500, I started hand numbering the cert's. Like 1A,2A,3A,4A,5A for the next batch, then 1B,2B,3B,4B,5B...
well you get the picture, I also date the cert's and then copy all.

I still cannot track them 100%. but in a dispute the handwritten tracking #'s would help me (and them), figure out which group is which....my first 2 of 4 batch posted within 3 weeks of mailing from within Michigan.