In many businesses, the same sale appears in several places: an invoice, a ledger entry, a bank record and a spreadsheet someone keeps for reporting. When those copies disagree, people spend their time working out which one is right.
A canonical transaction is the single, authoritative record of what happened. Ledgers, balances and reports are derived from it rather than maintained separately. If a figure looks wrong, you can trace it back to the transactions that produced it.
The same principle shapes how corrections work. Instead of silently editing a posted entry, a reversal or adjustment records the change, so the history stays intact and reviewable.
FYBB Books is being built around this transaction-led core, with every report intended to come from the same source of truth. It is a simple idea that makes the rest of the system easier to trust.