Field Notes · 28 January 2026
Firmware strings that belong on the inventory sheet
Model names alone do not age a fleet. Capturing the firmware string during an offline inventory keeps rotation decisions honest.
Registers that list only “Ledger” or “Trezor” and a colour tell you almost nothing six months later. During a firmware and inventory baseline we write the exact string shown on the device screen while authorised staff watch.
Why the string matters
Manufacturer advisories rarely say “all devices.” They cite builds. If your sheet lacks the string, you cannot decide which units hit a rotation trigger without powering every wallet again under pressure.
How we capture it safely
We never ask for seed cards. The device is unlocked only by your staff, far enough from windows for shoulder-surfing comfort. We copy the firmware field onto paper first, then into the baseline register. Photos of the device face are optional and never include recovery material.
Linking to rotation
On a full fleet review, firmware age is one column among several. A current build does not excuse a missing recovery proof or an unmapped spare. The offline wallet tracker checklist keeps those columns side by side so one green cell cannot hide another gap.