Audience: maintainers running real-hardware follow-up on unresolved native command families.

This page replaces the old repository-level TODO list for native command follow-up. Keep normal user docs focused on known-good workflows and keep this page for native-command follow-up policy and interpretation.

Public Policy

Keep unresolved native command behavior visible. Do not add fallback behavior that silently swaps in a different command family.
Keep unresolved native commands in the public API, but describe them as native probes on the validated real-hardware setups instead of known-good workflows.
Treat read-qualified-words / write-qualified-words over 0601/1601 as the practical public path for U...\\G... / U...\\HG... access on the current setup.
Treat native qualified commands as unsupported diagnostic probes, not as a supported U... access path.

Active Items

Track current follow-up items in TODO.md.

Implementation Gaps

Track current implementation gaps in TODO.md.

Follow-up Rules

Add every new hardware result to docsrc/validation/reports/HARDWARE_VALIDATION.md.
Add or extend the consolidated report under docsrc/validation/reports/ for that hardware target, including raw evidence and command examples.
Keep the top-level README.md summary short. Push detailed failure evidence into validation docs.
Preserve request-shape conformance tests before treating hardware rejection as an encoder bug.
Record the exact serial settings, PLC model, and native PLC end code for every new result.
Run shared real-UART probes strictly serially. Parallel access on the same serial port can produce mixed RX fragments and invalidate the result.
Keep FX5U notes aligned with its serial manual: 0801/0802 unsupported, DX/DY/V/ZR outside the validated subset.
Do not turn unsupported access paths into backlog items. For long timer / long retentive timer contact+coil devices, keep LTS/LTC/LSTS/LSTC on the structured LTN/LSTN 0401 path.
Re-read the device-specific considerations before assuming that a rejected command family is a bug. LTN/LSTN/LCN are not treated as monitor targets here because the manual-listed paths are 0401, 0403, and 1402 (LCN also 1401), while LZ explicitly lists 0801.