Keep three evidence channels separate
| Channel | Question | Limit |
|---|---|---|
| Visible page | Are the visible details legible and internally consistent? | An image cannot expose every physical feature |
| Machine-readable text | Does the text meet the relevant structure and check-digit rules? | Consistent text does not prove issuance |
| Authorized authentication process | Can stronger evidence establish authenticity and holder binding? | A browser checksum calculator does not perform this process |
Compare the correct document edition, not an unrelated example. PRADO is one public place to locate official document-reference entries. A difference in a scan still needs interpretation in light of capture quality and the exact edition. Council of the EU: PRADO document reference library
What an MRZ result means
A machine-readable zone uses a constrained alphabet and specified field conventions. Check digits detect certain transcription inconsistencies. The arithmetic is reproducible; the result does not tell you whether a government issued the document. ICAO Doc 9303, Part 3: check-digit method
An OCR error and an intentionally changed field can both create a mismatch. A match can also occur for different inputs. Record “checksum matches” or “checksum differs,” not “passport valid” or “passport fake,” when arithmetic is the only evidence available.
A review handoff that helps the next person
- State which edition or reference you used.
- Describe exactly which field or feature was unclear.
- Separate observations from your interpretation.
- Explain which additional authorized check could resolve the issue.
- Avoid sending a full identity image when a minimized issue description is sufficient.
When the task is software testing
A passport-generator query may actually mean “I need sample fields for an onboarding form.” Use a fictional passport record with an impossible test issuer, a NOT-VALID number and no machine-readable zone. Date-order and required-field tests do not require a usable passport.