Labor Vector asks for one thing: an email address, typed in by the person who owns it, with a box ticked to agree to the emails.
The address, which list it joined (the digest, or a follow of one record, and which), the date, and the page the form was on. Nothing else: no name, no IP address, no tracking.
In a private store of the site's host, Vercel, shared with its sibling sites machinemediation.org and provenanceerasure.org. Private means no web address serves the records; only the sites' own signup code and their operator can read them. Addresses are never published, sold or shared.
The emails the person asked for: the digest, or notice that a followed record changed. No email has been sent yet; the list is gathered first. Every email will carry a one-click unsubscribe, and an unsubscribe removes the address from that list.
Anyone can ask for their address to be deleted entirely, from any email, and it is.