====== P4-REQ-21-6-011 ====== [[dido:99_annexes:annex-d-requirements:part-04:start| Return to Requirements]] ===== Statement ===== IDL structures SHALL NOT redefine FX logical information structures. ===== Source ===== Part 4, Section 21.6: Information Structure Mapping Requirements. ===== Rationale ===== IDL structures are selected Phase 0 implementation representations of logical information structures. They define implementation-level data representation, not architectural meaning. Preventing IDL structures from redefining logical information preserves the authority of the Part 3 FX Demo Logical Profile and allows implementation representations to evolve independently under governance. ===== Applies To ===== This requirement applies to: * IDL structures; * source IDL files; * generated types; * DDS Topic mappings; and * FX logical information structures. ===== Verification ===== Verification SHALL confirm that IDL structures do not redefine FX logical information structures. Verification activities should include review checks confirming that: * logical information meaning remains governed by Part 3; * IDL structures are treated as implementation representations; * implementation-specific fields or constraints do not silently alter logical meaning; and * changes affecting logical meaning are governed at the applicable logical layer. ===== Traceability ===== This requirement preserves the separation between Part 3 FX logical information structures and their Phase 0 IDL representations. Related requirement identifiers: * [[dido:99_annexes:annex-d-requirements:part-04:p4-req-21-6-002]] * [[dido:99_annexes:annex-d-requirements:part-04:p4-req-21-6-010]] * [[dido:99_annexes:annex-d-requirements:part-04:p4-req-21-6-012]] Related source section: * [[fxdemo:04-part:21-phase-0-implementation-requirements:21-6-information-structure-mapping-requirements:start]] ===== Status ===== Draft ---- © 2026 Dido Solutions, Inc. and Jackrabbit Consulting, Inc.