Keep a field-level revision log and refresh affected label calculations
Use a concrete change ledger to distinguish display conversions from source corrections, invalidate dependent results and reverse an edit safely.
When you edit a saved label record, identify which outputs depend on the changed field. A unit-display adjustment and a corrected source quantity need different handling. A field-level revision log lets you update the right results while retaining the evidence behind earlier versions.
Start with a small dependency map
In this fictional example, record P014-v1 stores sodium as 180 mg per 30 g and protein as 6 g per 30 g. Its sodium outputs are 600 mg per 100 g and 270 mg per 45 g portion. Its protein outputs are 20 g per 100 g and 9 g per portion.
The FDA label overview identifies the underlying panel fields. This revision workflow is an original recordkeeping method, not an official FDA procedure. Keep source quantities, display formatting and calculated outputs in separate fields.
Log the field before changing it
| Field and edit | Before | After | Source and reason | Affected outputs | Status |
|---|---|---|---|---|---|
| Sodium display | 180 mg | 0.180 g | Photo A; display-unit choice | Displayed units only | Quantity unchanged |
| Sodium source amount | 180 mg | 150 mg | Clearer photo B; transcription correction | Sodium concentration, portion and shared card | Pending recheck |
Add an edit identifier, editor and date to each ledger row. Preserve the original source text and image. For the first row, retain the same underlying quantity: 180 mg equals 0.180 g. A display in grams would show 0.600 g per 100 g and 0.270 g per portion. Relabeling a number without converting it is not a display-only edit.
Invalidate dependent results before replacing them
The second row changes the source quantity. Mark sodium-derived outputs outdated while you verify photo B belongs to this exact record. After verification, 150 ÷ 30 × 100 = 500 mg per 100 g, and 150 ÷ 30 × 45 = 225 mg per portion. Attach those results to P014-v2 and change their status to current.
The protein source fields did not change, so their 20 g and 9 g outputs remain valid. A serving-weight correction would affect both nutrients instead. Keep a list of dependencies rather than marking every output current merely because one calculation was refreshed.
Make rollback another recorded edit
If photo B later proves to be the wrong variant, record a reversal with its reason. Restore P014-v1 only if its evidence is still verified; otherwise leave the sodium field unresolved. Restoring 180 mg also restores the derived 600 mg and 270 mg values. Retain the rejected version and identify any shared card needing a dated correction. Do not erase the history or leave an old output labeled current after its source has been invalidated.