The system you document in belongs to the institution. So does the record. If your judgment is questioned later, your reasoning may be reconstructed from their record with the outcome known. What it can be read to say may not be what you meant at the time.

Professionals have always kept notebooks. Writing down your reasoning and keeping your own record is old, ordinary, and yours to do. This ledger continues the practice. It asks nothing of your institution, touches nothing that belongs to it, and needs no one’s permission.

Double Turnstile is the record you keep — your judgment, in your custody: your reasoning, independently timestamped the moment you make it, and fixed to the exact files you relied on — by fingerprint, never by copy.