7.13 Good to know — accounts

The ledger is the audit trail. Reversed batches remain, linked to their reversals; nothing posted is ever deleted or edited (1.6). An auditor's questions are answered from GL Batches and Journal Entries, not from memory.
A closed period refuses everything — including auto-post. A document approved into a period that has since closed stays unposted, with its reason; reopen the period, or let the correction land in the open one, as your accountant directs.
"—" is an honest balance. A foreign bank whose own-currency balance cannot yet be known (unadopted, 7.6) shows "—" on Cash Position and in the bank pickers. The home-currency books are complete regardless; the dash guards only the second denomination.
Cash Position is book truth. It can differ from the bank's own app until a reconciliation agrees them; the last-reconciled date beside each balance tells you how much that matters today.
Budgets protect nothing. They neither block nor approve spending; they make drift visible early (7.6). Protection lives in permissions and credit controls.
Your chart is yours; its classes are everyone's. Rename groups and accounts freely; the five classes are the shared frame that keeps statements, cockpits and exports speaking the same language (7.5).