Yes, and it will be.
There were 60 questions tagged signature when I started. When my edits go through, there should be 1. digital-signature and email-signature together fit 47 of them (some already had the relevant more-specific tag); code-signing fit 6, hashing fit 1, user-agent fit 1, and I'm not sure what to do with the following 2.
These ones are about using handwritten signatures in digital documents:
- How can I add a signature field in a PDF? (not a digital signature)
- How can I sign a PDF document quickly and cheaply?
This one is about using a static image (an “image signature”) as a form of signature analoguous to a handwritten signature:
The network has rejected my retagging-only edit to the remaining question for some odd reason.