Overview
ISO 7499:2024 - Technical product documentation (TPD) - Unique integral feature identification (UIFI) defines a human‑readable system for uniquely identifying the integral features of a part within technical product documentation. The standard specifies an integral feature indicator composed of a graphical symbol (leader + reference line) and an alpha‑numerical label (integral feature identifier). It also covers graphical symbols and the proportions and dimensions for simplified indication of repeated features (see Annex A).
Keywords: ISO 7499, unique integral feature identification, UIFI, technical product documentation, integral feature identifier, TPD, CAD.
Key topics and technical requirements
- Scope and purpose: Provide a clear, readable identifier for integral features to improve communication, traceability and documentation across design, manufacturing and inspection workflows.
- Graphical symbols: Definition of the integral feature indicator symbol (leader line + reference line) and symbols for enumeration direction of repeated features (circular and multilinear/matrix).
- Alpha‑numerical labels (UIFI rules):
- Labels shall be unique and may follow user rules.
- Recommended format: single or repeated capital letter (e.g., A, BB, CCC).
- Avoid letters that cause confusion: I, O, Q, X, Y, Z.
- Prefixed capital letter (e.g., 2B) is recommended over long repeated letters for readability and electronic search efficiency.
- Postfixed enumeration allowed for indexed features (e.g., 2A1, 2A2) - primarily for repeated, portioned or compound features.
- Usage guidance: Identifiers may be used as datum feature identifiers (per ISO 5459) and can be combined with specifications where needed.
- Simplified enumeration: Graphical symbols and rules for indicating direction and enumeration of repeated features are specified; proportions are defined in Annex A.
Practical applications and users
ISO 7499:2024 is practical for:
- Mechanical designers and CAD users who need human‑readable identifiers for model features.
- Manufacturing engineers and machinists for unambiguous work instructions and secondary operations.
- Metrologists and quality engineers for measurement planning, reports and nonconformity traceability.
- Technical writers and document controllers preparing nomenclature drawings, SOPs, FMEA, tolerance stack‑ups, change requests and customer communications.
- CAD vendors - encouraged to adopt harmonized UIFI implementations to support interoperability.
Benefits include improved verbal/written communication, easier referencing in measurement reports and SOPs, clearer nomenclature drawings, and better traceability between drawings and other TPD.
Related standards
- ISO 5459 - Geometrical tolerancing - Datums and datum systems (datum feature identifiers referenced).
- ISO 81714‑1 - Design of graphical symbols for use in technical documentation - Basic rules.
- Additional context referenced: ISO/TS 21619 (use of drawings in design/manufacturing/verification).
For implementers, follow ISO 7499 to make feature identifiers human‑readable, unique and consistent across TPD and CAD systems.