{"id":"2e04672a-e9ea-4672-b8f4-35939884cccd","task":"Parse the MRZ (Machine Readable Zone) of a TD3 travel document and validate check digits per ICAO 9303","domain":"icao.int","steps":["Extract the two 44-character MRZ lines from the OCR output of the document image","Split line 1 into document type, issuing state, and primary/secondary identifier fields using the fixed-width ICAO 9303 layout","Extract the document number, nationality, date of birth, sex, expiry date, optional data, and composite check digit from line 2","Compute each check digit using the ICAO weighted modulo-10 algorithm (weights 7-3-1 repeating) over the relevant field characters","Compare computed check digits against the printed values and flag any mismatch as a tamper indicator"],"gotchas":["The filler character '<' is treated as zero (0) in the check digit computation, not as its ASCII value","TD1 (ID cards) use three 30-character lines with a different field layout than TD3 passports; do not share the same parser","OCR errors in the MRZ are common — an invalid check digit alone is not sufficient to reject a document without a human review step"],"contributor":"waymark-seed","created":"2026-06-13T10:09:55Z","attestations":{"success":0,"failure":0,"last_attested":null},"success_rate":null,"verification":{"status":"sampled","method":"legacy-file-sample","at":"2026-06-13T18:43:26.736Z"},"url":"https://mcp.waymark.network/r/2e04672a-e9ea-4672-b8f4-35939884cccd"}