Six distinct meanings
- Serial allocation date: a block reserved for planned production.
- Reported production period: a separately sourced claim about actual manufacture.
- Model introduction or sales period: contextual history, not a unit date.
- Exact documented unit: an individual number named by an archival-quality source.
- Broad lens year estimate: a coarse sequence that does not identify a model.
- Detailed model allocation: a model-named block that still normally represents planning.
Source and rights gate
Every source is classified by quality, coverage, limitations, rights status, and reuse decision before a fact enters the production data. Restrictive sources can flag a question for independent checking, but they do not become an import license.
CameraQuest is verification-only because it expressly prohibits republication. Red Dot Camera and the public Leica Serial Number Library repository also remain verification-only because no reusable data license was established. Camera-Wiki's textual content is GFDL 1.3 and supports attributed, normalized lens-year facts. No third-party photographs, source prose, layouts, or database exports are used.
Confidence
| Class | Meaning |
|---|---|
| high | Official or archival individual evidence, or strong independent agreement on the relevant fact. |
| medium | A credible specialist or factory-list transcription supports the assignment, but corroboration is incomplete. |
| low | A coarse estimate or known boundary anomaly affects the answer. |
| conflicting | Sources assign different boundaries or meanings. The disagreement is shown. |
Validation
The release validator checks positive integer serials, reversed ranges, inclusive quantities, duplicates, model and source references, unexpected overlaps, uncovered intervals, documented-unit records, and a deterministic SHA-256 checksum.
Release checksum: 300c178ea095b013822b5721749ef215d1fdc5e89573e71ec051d9b8ff7aed56
Corrections
Corrections enter a private review queue. Nothing is published automatically. A change must identify the affected range, provide a source locator and rights information, explain the proposed interpretation, pass validation, and appear in release notes.