====== 4.5 Explicit Information Structures ====== [[fxdemo:02-part:start | Go To Top ]] The Logical Architecture defines information exchange through logical [[dido:99_annexes:annex-b-terms-and-definitions:l:logical_data_structure_definition|Data Structure Definitions]] and logical [[dido:99_annexes:annex-b-terms-and-definitions:l:logical_data_structure_instance|Data Structure Instances]]. Logical [[dido:99_annexes:annex-b-terms-and-definitions:l:logical_data_structure_definition|Data Structure Definitions]] identify the structure, meaning, and constraints of information classes at the PIM level. Logical [[dido:99_annexes:annex-b-terms-and-definitions:l:logical_data_structure_instance|Data Structure Instances]] represent populated occurrences that Nodes exchange, record, interpret, validate, or use as [[dido:99_annexes:annex-b-terms-and-definitions:e:evidence|Evidence]]. The Logical Architecture does not prescribe IDL, Protocol Buffers, JSON Schema, XML Schema, Avro, OpenAPI, database schemas, ontology classes, or generated language types. Later implementation profiles select those representations. ---- © 2026 Dido Solutions, Inc. and Jackrabbit Consulting, Inc.