It occurred to me today that it's been a few years since I first participated in the Thawte Web of Trust (for cryptographically secure email signatures). Sure enough, it looks like I was approved as a notary just over five years ago, on 24 April 2004. Thawte notaries are required to keep copies of documentation for assertions they make for five years. I think. So, I looked it up:
Retention of Copies
Each thawte Notary must retain a copy of the identifying documentation used to confirm the member's identity for every assertion made by that thawte Notary.
thawte Validation Statement
The member and the thawte Notary must both sign a copy of the "Statement of Validation" provided by thawte during the identity assertion process. The thawte Notary must keep this signed statement on record for 5 years.
So which is it? An identity assertion requires the notary to obtain two pieces of paper - a copy of the other person's identification and a sheet that both parties sign. From reading the above, it looks like the signed Statement of Validation only needs to be kept for five years, but the copy of the identifying documentation must be kept indefinitely. I think I'll try to ask them, there's a contact form on the site.