The short version, because there is not much to disclose:
- Your workbook never leaves Excel. Marks, sign-offs, legends, and reports are written directly into your file on your device.
- Like other Office add-ins, it loads its code and Microsoft’s Office runtime over the network. These requests do not contain your workbook data. License validation sends your key and installation details; the free tier does not make a license request.
- Your key, settings, custom marks, and custom image marks are stored in your local Office add-in storage only.
- No analytics, no cookies, no advertising, no automatic error reports.
The full document is the Audit Tickmarks privacy policy; the terms of use are here.