## Draft - Standard: EN 304 621 (Network Management Systems) - Draft version: - Section: \<TBD: Conformance language / validation / error handling\> ## Problem / Observation Ambiguous acceptance statements lead to divergent implementations. NMS behavior for failed validations, rejected configs, and policy violations must be explicit and testable. ## Proposed change (exact text) Add: "Where the standard states that an implementation 'accepts' an input, change request, or condition, the standard SHALL define the operational meaning, including validation steps, default decision (apply/reject/quarantine), logging requirements, and a failure taxonomy (e.g., validation failure, policy violation, not admissible). The standard SHALL avoid ambiguous acceptance that could lead to divergent implementations." ## Rationale - Ensures deterministic behavior and testability. - Improves audit clarity and operational predictability. ## Conformance impact - PASS if failure behaviors are explicit and testable. - FAIL if acceptance/failure semantics remain undefined.