ISO 7499:2024

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.