Glossary
Fiscal log immutability (ISCA Guard)
Logical lock preventing retroactive modifications
Scell.io implements an ISCA Guard at the Eloquent level that blocks any modification of a fiscal field on an invoice / credit note / closure in a status other than `draft`. Any attempt is logged in `fiscal_audit_logs` with `critical` severity. Combined with SHA-256 hash chain, this makes the fiscal log effectively immutable.