Limitations and unverified properties

The following boundaries are established by the current source or are not established by it:

Property	Current status
Sheet layout	Fixed 40-question, four-choice geometry with fixed coordinates. Configurable layouts are unsupported.
Multiple marks	Preserved as sorted strings such as AC; they do not match a single-letter key.
Authentication	Not implemented or verified.
Upload limits	No application-level limit is defined in the repository.
Input validation	No product-specific validation or structured 4xx contract is defined.
Production OCR accuracy	Unverified. Real-sheet tests use the test OCR double.
Concurrency and capacity	Unverified.
Debug retention	Unconfigured. Files may accumulate under data/debug.
Public deployment safety	Not established; use only in a trusted or isolated deployment until hardening is added.

The five checked-in fixtures demonstrate current behavior on those images only. They are not a benchmark for other cameras, lighting, sheet designs, handwriting, or operating environments.