ISO - International Organization for Standardization

This document specifies the requirements and procedures for the calibration of primary and secondary reference solar cells under the air mass zero (AM0) spectrum. It is applicable to both single-junction and multi-junction solar cells.

This document specifies a process for a medical laboratory to identify and manage the risks to patients, laboratory workers and service providers that are associated with medical laboratory examinations. The process includes identifying, estimating, evaluating, controlling and monitoring the risks. The requirements of this document are applicable to all aspects of the examinations and services of a medical laboratory, including the pre-examination, examination, and post-examination aspects including accurate transmission of examination results into the electronic medical record, as well as other technical and management processes described in ISO 15189. This document does not specify acceptable levels of risk. This document does not apply to risks from post-examination clinical decisions made by healthcare providers. This document complements the management of risks affecting medical laboratory enterprises that are addressed by ISO 31000, such as business, economic, legal, and regulatory risks.

This document addresses the safety of persons and premises when using devices and appliances ("products") with interfaces to a communications network in a home or building ("premises"). Such products are called "networked appliances" and "networked products." This document specifies basic requirements for safer operation of products that can be controlled remotely via a connection to a communications network. The network can enable such products to form integrated applications. These products can interact via the premises network and can be controlled remotely from within the premises and from a wide area network outside connected to the premises network via a communications gateway. Recommendations and methods for remote-control message screening and guidelines for selecting messages to minimize risk are specified. These specifications can enhance safety in a home control system (hcs). The safety requirements specified in this document apply together with any relevant product safety standards. NOTE 1 ISO/IEC HES standards are identified by HES or "Home Electronic System" in the title. NOTE 2 This document addresses conditions of normal use and fault conditions throughout the lifetime of a product. Sabotage, force majeure, and intentional damage are not addressed in this document. NOTE 3 This document is not intended for safety-related equipment such a fire-detection and suppression system. NOTE 4 "Networked applications" and "networked products" describe the same category of devices and are used interchangeably in this document.

This document provides the principles and rules for the naming of general terms in the field of nanotechnologies. This document gives guidance for the naming of a range of concepts, materials, objects, items and phenomena using a series of identified qualifiers, following the convention described within this document. NOTE Additional terms and definitions that relate to nanotechnologies are provided in ISO 80004-1:2023.

This document specifies the characteristics of general-purpose eddy current instruments and provides methods for their evaluation and verification. This document can be completed by an application document specifying acceptance criteria for the characteristics of the eddy current instrument. Where accessories are used, these are characterized using the principles of this document (e.g. additional external amplifiers).

This document specifies a laboratory test method for microbiologically influenced corrosion (MIC) of oil and gas transmission pipelines, including the principle, apparatus, sources of strains, solutions, specimens, sterilization, procedure, results and report. This document applies to the MIC test of metals and alloys for internal surfaces of oil and gas transmission pipelines.

This document specifies requirements for reference next generation nucleotide sequences.[1][2] This document is applicable to all verified next generation (VNGS) nucleotide sequences determined by next generation sequence (NGS) technology that are accessible on the semantic web and included in a database (public or private).[3][4][5][6]

This document specifies the properties and characteristics of typical vertical joints between two prefabricated concrete external wall components irrespective of whether these joints coincide with joints between the external wall and an internal wall or column. However, the characteristics of joints which are involved in the structural behaviour of buildings are not specified in this document. This document is applicable to all public or private buildings, used as dwellings, offices, educational or hospital premises.

This document specifies an instrumental method for determining the yellowness index and change in yellowness index on clear, translucent, or opaque plastics. NOTE Change in yellowness index is often used to evaluate the effect of environment, e.g. heat, UV exposure, etc., on colour stability.

This document specifies a method for the determination of the penetration temperature of thermoplastics using thermomechanical analysis (TMA). NOTE This method can also be used to measure the softening point.

This document specifies a general method of test for determining the oil absorption value of a sample of pigment or extender. The oil absorption value is usually required to be compared with the value determined at the same time on an agreed sample of the product.

This document defines two performance levels for welded joints, namely Basic Demand and Critical Demand, for longitudinal tensile strength of weld metals, impact toughness of weld metals and heat affected zones (HAZ) to suit the level of seismic performance specifications required for welded steel structures. This document supplements the provisions of the standards or codes for welding procedure qualification in the application of new steel materials, welding consumables, or complex joints, for welds that require the performance of Basic or Critical Demands as specified by the engineer in the contract.

This document specifies the characteristics of grooved pins with one-third-length centre oval grooves (with closed ends), in steel and stainless steel, and with a nominal diameter from 1 mm to 25 mm. These grooved pins are designed to fulfil the main following functions: relative rotation of the assembled parts, and positioning or guiding, with an easy installation (due to its symmetrical shape) and a medium level of pull-out resistance (due to the elastic fit behaviour of the pin). The general requirements (including functional principles for grooved pins and assembly) are specified in ISO 13669.

This document specifies principles and requirements for a body operating certification of persons and includes the development and maintenance of a scheme for certification of persons. NOTE 1 For the purposes of this document, the term "certification body" is used in place of the full term " body operating certification of persons", and the term "certification scheme" is used in place of the full term “scheme for certification of persons”. NOTE 2 Annex A contains principles for certification of persons.

This document specifies requirements and provides guidance that enable an organization to reduce its energy-related greenhouse gas (GHG) emissions (ERGE). This document is applicable: to any organization regardless of its type, size, complexity, geographical location, organizational culture or the products and services it provides; to energy-related Scope 1 emissions and Scope 2 emissions; irrespective of the quantity, use or types of energy consumed. This document requires demonstration of absolute ERGE reduction aligned with ERGE target(s). Annex A provides information on the relationship between ISO 50001:2018 and this document. Annex B provides information on GHG emissions and GHG emission factors. Annex C provides guidance related to the decarbonization planning.

This document describes the basic characteristics of fluoroethylene vinyl ether copolymer (FEVE) type fluoropolymer topcoats and their coating systems. Information on the weathering performance of the fluoropolymer topcoats and associated coating systems for over 30 years is also provided.[1]],[[4]]-[[12] This document covers: weathering data of FT (FEVE fluoropolymer topcoat); chemical analysis of outdoor exposed coated panels focusing on the paint surface and their cross-sections. This document does not include FEVE type waterborne fluoropolymer topcoats and their coating systems.

This document specifies the general principles for the establishment of herbal reference substances, covering production, quality control, report, instruction and labelling, packaging, storage and transportation. This document applies to herbal reference substances that are sold and used as reference standards for the quality control of herbal medicines in international trade, including raw materials and finished products.

This document specifies for passenger lifts and goods passenger lifts: the verification of door locking devices; the verification of safety gears; the verification of overspeed governors; the verification of buffers; the verification of safety circuits and SIL-rated circuits; the verification of ascending car overspeed protection means; the verification of unintended car movement protection means; the verification of rupture valves and one-way restrictors; the verification of suspension and compensation means; the discard criteria for suspension means and sheaves; the calculation of guide rails; the calculation of rams, cylinders, rigid pipes and fittings; the evaluation of the traction; the evaluation of the safety factor on suspension means; the pendulum shock tests; the fault exclusion for electric and electronic components; the design rules for SIL-rated circuits. This document is not applicable to passenger lifts, goods passenger lifts or lift components, which are installed or manufactured before the date of its publication.

This document specifies the safety rules for lifts permanently serving buildings and constructions and intended for the transport of persons or persons and goods. It applies to traction lifts, positive drive lifts and hydraulic lifts that: serve specific levels; and have a rated speed exceeding 0,15 m/s; and have an enclosed car; and move along guide rails inclined not more than 15° to the vertical; and are indoor or weather-protected. This document also applies to the electrical equipment of these lifts including the lighting and socket outlets in the well. This document specifies safety rules related to: persons to be safeguarded: users, including passengers, maintenance and inspection personnel; persons at the landings and outside of the well, or any machinery space and pulley room, who can be affected by the lift. property to be safeguarded: loads in the car; components of the lift installation; building in which the lift is installed. This document does not specify additional requirements for: lifts serving buildings with requirements for seismic conditions; lifts serving buildings with requirements for accessibility; lifts exposed to vandalism; lifts which can be used for firefighting and evacuation purposes under firefighters control; lifts which can be used to support faster evacuation of persons with disabilities; the behaviour of the lift when the control system of the lift receives a recall signal(s) in the event of fire in a building. This document is not applicable to passenger and goods passenger lifts, which are installed before the date of its publication.

This document specifies the mounting dimensions of the accessories regarding interchangeability for 16 MPa (160 bar) compact cylinders conforming to ISO 6020-3. The accessories are applied to mounting with cylinders manufactured in accordance with ISO 6020-3. This document covers the following accessories of which the identification code is specified in ISO 6099: AP2 rod clevis, internal thread (see Figure 1 and Table 1); AP4 rod eye, plain, internal thread (see Figure 2 and Table 2); AA4 - L pivot pin (locking plate) (see Figure 3 and Table 3); AL6 locking plate for pivot pin (see Figure 4 and Table 4); AA4 - S and AA4 - R pivot pin plain (see Figure 5-6 and Table 5 respectively). The design of these accessories is based on the maximum forces derived from pressures and bore diameters of the cylinders specified in ISO 2944 and ISO 3320.

This document contains requirements for the competence and impartiality of bodies performing inspection, and for the consistent operation of their inspection activities.

Motorway chauffeur systems (MCS) perform Level 3 automated driving on limited access motorways with the presence of a fallback-ready user (FRU). This document describes a framework of MCS including system characteristics, system states and transition conditions and system functions. This document specifies requirements for the basic set of functionalities of a MCS, and test procedures to verify these requirements. The requirements include vehicle operation to perform the entire dynamic driving task (DDT) within the current lane of travel, to issue a request to intervene (RTI) before disengaging, and to extend operation and temporarily continue to perform the DDT after issuing an RTI. Requirements and test procedures for additional functionalities (such as lane changing) are provided in other parts of the ISO 23792 series. Means related to setting a destination and selecting a route to reach the destination are not within the scope of this document. This document applies to MCS installed in light vehicles[9].

This document describes a test method for the determination of the flash point of chemicals, lube oils, fuels including aviation turbine fuel, diesel fuel, diesel/biodiesel blends and related products. The precision of this method has been determined over the range of 24,5 °C to 229,5 °C. NOTE Apparatus can determine the flash point at higher or lower temperatures than the precision range, however the precision has not been determined.

This document describes a standardized methodology and framework for the development and representation of an ontology that supports a global, open-source approach to implementing the ISO standards on the identification of medicinal products (IDMP) (ISO 11615, ISO/TS 20443, ISO/TS 20451, ISO 11238; ISO/TS 19844, ISO 11239, ISO/TS 20440, and ISO 11240). Realization of the full potential of IDMP requires fully self-describing data. For this purpose, this document describes a methodology and framework that complements the existing conceptual and logical models in the ISO documents on IDMP with an IDMP ontology that enables deep, semantic interoperability based on findable, accessible, interoperable and reusable (FAIR) data principles. This methodology and framework enhance the usage of the IDMP data model as the foundation of medicinal product identification and will ultimately enable collaboration towards drug safety and overall operational efficiency. This document also describes a methodology for the agile adaptation of the ISO documents on IDMP in connection with cross-jurisdictional IDMP-related legislation and initiatives. This document is intended to be complementary to and independent from formal regulatory guidance. Thus, it enables cross-jurisdictional consistency and supports stakeholders in their regional implementations of IDMP standards. This document does not mandate any specific ontology as an implementation tool, nor is it an instructional guideline on how to build ontologies, which is out of scope of this document. This document includes key use cases described in the ISO documents on IDMP ISO 11615, ISO 11238 and ISO/TS 19844, as well as further use cases arising from the comprehensive deployment of the ISO documents on IDMP via an ontological framework. Thus, an ontology that represents the IDMP standards aims to cover the complete collection of ISO standards on IDMP regarding key interoperability issues that implementing stakeholders are facing.

This document specifies quality requirements for the chart, test procedure and acceptance level for near, far, and colour vision acuity of NDT personnel. Information for grey scale perception and low contrast can be found in the annexes. This document also specifies the qualification requirements for personnel permitted to carry out the test. This document is only applicable to vision acuity under defined conditions similar to those encountered during routine NDT inspection. This document does not address an individual’s overall visual acuity and users are advised to consider the need for a general eye examination by specialist medical personnel to ensure general vision acuity.

This document outlines requirements for healthcare organizations to deliver diagnostic tests timely and accurately in a pandemic by leveraging innovative approaches to overcome the limitations of laboratory capacity as follows: mitigation of threats encountered in providing diagnostic services during a pandemic; consideration for quality assurance of diagnostic service provision in a pandemic context; possible response measures to the surge in diagnostic demand. This document does not cover the specific procedures involved in providing pandemic-response medical tests, such as the specimen collection protocols in the specimen collection units or screening stations (e.g. walk-through or drive-through), experimental procedures and the quality management systems of medical laboratories. Furthermore, this document does not address the pandemic responses related to the medical treatment of infected patients in care units (e.g. emergency unit and in-patient unit) and the transferring of confirmed patients within the healthcare organization during a pandemic.

This document specifies a gradient column method for the determination of the density of non-cellular moulded or extruded plastics or pellets in void-free form.

This document describes methods for simulating the mechanical loads that can be imparted to passive fire protection (PFP) materials and systems by explosions resulting from releases of flammable gas, pressurized liquefied gas, flashing liquid fuels, or dust that can precede a fire. These methods can be used to determine the resistance of passive fire protection materials to such events. This document considers PFP materials applied to panels, plates, etc. that can be used as divisional elements. The loading on this type of element predominantly results from explosion overpressure applied and drag loadings are typically minimal.

This document: establishes requirements for the geological storage of CO2 streams in a way that minimizes risk of CO2 losses; is applicable for both onshore and offshore geological storage within permeable and porous geological strata including hydrocarbon reservoirs where a CO2 stream is not being injected for the purpose of enhancing hydrocarbon production; includes activities associated with site screening and feasibility investigation, characterization, design and development, operation of storage projects, and preparation for project termination; recognizes that the geological characteristics, physical boundaries, management, intrinsic technical risk and uncertainties, of each site are likely to be unique for each project and that intrinsic technical risk and uncertainty will be dealt with on a site-specific basis; provides requirements for integrated project management, including elements of risk management unique to the geological storage of CO2 streams; and establishes a methodology for quantifying the net mass of CO2 that geological storage projects store in storage unit(s). Figure 1 illustrates the limits of this document. This document does not apply to: temporary storage in tanks or by other means; the post-termination phase; injection of CO2 for enhancing production of hydrocarbons or for storage associated with CO2-EOR; disposal of other acid gases except as considered part of the CO2 stream; disposal of waste and other matter added for purpose of disposal; or underground storage using any form of buried container. If production of hydrocarbons in commercial quantities occurs from the storage unit(s), the storage project is outside of the scope of this document and ISO 27916 applies to CO2 storage. A CO2-EOR project that has stored CO2 in association with CO2-EOR can transition to operate under this document after all production of hydrocarbons from the storage unit(s) has ceased.

This document specifies the Digital Negative (DNG) image file format. A DNG file meets the requirements provided in this document.

This document defines adaptive thermal comfort and its mechanisms, and describes current approaches to predict adaptive thermal comfort. This document applies to human thermal comfort in indoor built environments and seasonal adaptive processes. It is applicable to healthy humans exposed to indoor environments where thermal comfort is desirable, but where moderate deviations from thermal comfort occur, in the design of new environments or the assessment of existing ones.

This document specifies the methods commonly available for separating adhesively bonded joints enabling repair and improving recycling. This document applies to adherends made of metallic and non-metallic inorganic material, plastics including both filler-containing and fibre-reinforced types, wood and wood-based materials, coated materials, adherends of natural and polymeric fibres as well as paper and cardboard.

This document specifies requirements and recommendations for the provision of health and social care services for older persons by healthcare and social care workforce, irrespective of whether the service is provided in the persons own home or in a care home. The services concerned also include short-term care e.g. respite care, enablement, and rehabilitation. Care services are provided in a variety of settings. While this document focuses on services provided in care facilities and care at home, including preventive, responsive, palliative and end of life care, many of the requirements and recommendations can be applied to the provision of care services in any setting. Service provision is based on the individual needs and preferences of the older person to assist self-determination, participation, safety, and security. The document encompasses the holistic needs of older persons receiving care at home and at care homes and the workforce, taking into consideration principles of equity, diversity, and inclusion. This document applies to all providers of care and support to older persons irrespective of size, structure, legal set up, or funding model (i.e. public, private or non-profit). This document does not cover standardization of clinical guidelines, medical devices and building codes (engineering and structural).

This document specifies good clinical practice (GCP) for the design, conduct, recording and reporting of clinical investigations carried out in human subjects to assess the clinical performance or effectiveness and safety of medical devices. For post-market clinical investigations, the principles set forth in this document are intended to be followed as far as relevant, considering the nature of the clinical investigation (see Annex I). This document specifies the general requirements intended to protect the rights, safety and well-being of human subjects, users or other persons, ensure the scientific conduct of the clinical investigation and the credibility of the clinical investigation results, define the responsibilities of the sponsor and principal investigator, and assist sponsors, investigators, ethics committees, regulatory authorities and other bodies involved in the conformity assessment of medical devices. Other standards or national requirements can also apply to the investigational device(s) under consideration or the clinical investigation(s). NOTE For Software as a Medical Device (SaMD), where appropriate, demonstration of the analytical validity (the SaMD’s output is accurate for a given input), the scientific validity (the SaMD’s output is associated to the intended clinical condition/physiological state), and clinical performance (the SaMD’s output yields a clinically meaningful association to the target use) of the SaMD, the requirements of this document apply as far as relevant (see Reference [5]). Justifications for exemptions from this document can consider the uniqueness of indirect contact between subjects and the SaMD. This document does not apply to in vitro diagnostic medical devices. However, there can be situations, dependent on the device and national or regional requirements, where users of this document can consider whether either specific sections or requirements of this document, or both, can be applicable.

This document specifies the open system interconnections (OSI) application layer, the transport, and the network layer, as well as the mapping to the controller area network (CAN) data link layer protocol as specified in ISO 11898-1. The application layer specifies messages, which are mapped to CAN CC data frames using the classic extended frame format (CEFF). For messages exceeding the length of the CEFF-formatted data frames, this document specifies transport layer and network layer protocols based on the SAE J1939-21 recommended practice.

This document specifies a methodology to calculate the environmental impact of operational energy use for large yachts and enables the comparative assessment of a yacht's environmental performance against a defined baseline fleet. The method established herein is robust and based on the best available data, with transparency and comparability across various yacht types and technical characteristics. This document explicitly addresses operational energy consumption during the yacht's use phase, emphasizing the efficiency of onboard systems benchmarked against the found average operational profile and the environmental emissions coming from this energy, both upstream and downstream. It excludes behavioural variables arising from individual yacht operation patterns. Additionally, the production and maintenance materials and processes (upstream impacts), as well as yacht end-of-life considerations (part of downstream impacts), are outside the scope of this document. The operational profile specified in this document assumes that the yacht is professionally crewed year-round and capable of independent transoceanic voyages. NOTE For motor yachts, this operational assumption generally aligns with IMO MARPOL requirements, which apply to ships exceeding 400 GT that must be surveyed and certified for MARPOL compliance. Sailing yachts typically exhibit lower GT for equivalent length; however, their cruising behaviours align closely with motor yachts of comparable length.

This document provides formulas for the estimation of the PFH value of single-channel architectures as well as two-channel architectures with and without diagnostics in accordance with ISO 13849-1. The formulas presented in this document are based on Markov modelling and can be used as an alternative to the simplified procedure of ISO 13849-1 for estimating the quantifiable aspects of the performance level (see ISO 13849-1:2023, 6.1.8, Figure 12, and Annex K). They can also serve as an alternative to any other adequate method for estimating the quantifiable aspects of the performance level. NOTE Different estimation methods can vary in the resulting PFH values due to their nature. A certain variation is usually the consequence of different modelling approaches and unavoidable simplifications specific to the method. Other requirements of ISO 13849-1, e.g. on categories or software, are not addressed by this document.

This document specifies the quality and safety requirements for cultivated Cistanche deserticola stem derived from the plant of Cistanche deserticola Y.C. Ma. It is applicable to cultivated Cistanche deserticola stem that is sold as natural medicine in international trade, including Chinese materia medica (whole medicinal materials) and decoction pieces derived from this plant.

This document specifies the safety requirements for reciprocating internal combustion (RIC) engine driven generating sets up to 1 000 V alternating current (AC) or 1 500 V direct current (DC) and voltages above 1 000 V (AC) and not exceeding 36 kV consisting of an RIC engine, an AC generator including the additional equipment required for operating, e.g. controlgear, switchgear, auxiliary equipment. This document is applicable to generating sets for land and marine use (domestic, recreational and industrial application). This document is not applicable to generating sets used on board of seagoing vessels and mobile offshore units as well as on aircraft or to propel road vehicles and locomotives. This document is not applicable to gensets and components manufactured before the date of its publication. NOTE This document does not apply to arc welding equipment (IEC 60974 series). This document does not specify the special requirements needed to cover operation in potentially explosive atmospheres and is not applicable for such environments. The hazards relevant to RIC engine driven generating sets are identified in Table A.1. This document deals with the special requirements of test and safety design which are observed in addition to the definitions and requirements in ISO 8528-1:2018, ISO 8528-2:2018, ISO 8528-3:2020, ISO 8528-4:2025, ISO 8528-5:2025, ISO 8528-6:2023 and ISO 8528-10:2022, where applicable. This document specifies safety requirements in order to protect the user from danger.

This document provides requirements on identification and labelling of medicinal products from the point of manufacturing of packaged medicinal product to the point of dispensing the product. This document outlines commonly accepted international practices for automatic identification and data capture (AIDC) barcoding solutions for applications and applies to manufacturers, distributors, healthcare facilities and all parties involved in labelling and distribution of packaged medicinal products. These users can, however, consider the coding interoperability requirements for other AIDC technologies, e.g. radio frequency identification (RFID); that technology is not addressed in this document except as for information.

This document specifies how a transponder is activated and how the stored information is transferred to a transceiver.

This document specifies a method for quantitative determination of 17 2,3,7,8-chlorine substituted dibenzo-p-dioxins and dibenzofurans and dioxin-like polychlorinated biphenyls in sludge, treated biowaste and soil using liquid column chromatographic clean-up methods and gas chromatography/high resolution mass spectrometry (GC/HRMS). Detection by tandem mass spectrometry (MS/MS) can be used in an equivalent way. The analytes that can be determined with the method specified in this document are listed in Table 1. The limit of detection depends on the kind of sample, the congener, the equipment used and the quality of chemicals used for extraction and clean-up. Under the conditions specified in this document, limits of detection better than 1 ng/kg (expressed as dry matter) can be achieved. This method is “performance based”. The method can be modified if all performance criteria given in this method are met. This document is applicable for several types of matrices and validated for municipal sludge (see also Annex D for the results of the validation). NOTE In principle, this method can also be applied for sediments, mineral wastes and for vegetation. It is the responsibility of the user of this document to validate the application for these matrices. For measurement in complex matrices such as fly ashes adsorbed on vegetation, it can be necessary to further improve the clean-up. This can also apply to sediments and mineral wastes.

This document specifies the requirements for discretionary lane change (DLC) for motorway chauffeur systems (MCS) that perform Level 3 automated driving on limited access motorways. It also specifies the test procedures to verify the requirements. DLC is an additional functionality that can be added to an MCS conforming to the general requirements specified in ISO/TS 23792-1. Means related to setting a destination and selecting a route to reach the destination are not in the scope of this document. This document applies to the system installed in light vehicles.

This document describes a procedure for the evaluation of the uncertainty of measurements made with tactile Cartesian coordinate measuring machines (CMM). The measurement uncertainty evaluated in accordance with this document indicates the performance of the individual measurement operation, which is not the measuring capability nor test uncertainty when verifying the performance of the CMM against its maximum permissible errors (MPE).

The document specifies an overall read range performance indicator and its associated measurement methods for radio frequency identification (RFID) enabled tyres described in ISO 20911 and tagged in ISO 20909. The ultra high frequency (UHF) RFID band used covers 860 to 930 MHz. Methods applying to passenger cars, light commercial and truck vehicles classes of tyres as defined in subclause 4.1. Methods described have not been investigated for tyres beyond tyre classes defined in subclause 4.1.

This document specifies the determination of the absolute value of diacylglycerols as well as the degree of isomerization of diacylglycerols in vegetable fats and oils. 1,2-diacylglycerols are transformed to the more stable 1,3-isomers during storage or due to acidic catalysed reaction. NOTE Results obtained using this document have not been compared with results obtained using ISO 29822.

This document specifies terms and definitions of engineered stone intended for use in finished products such as countertops and vanities, floor and wall coverings and accessories including its raw materials, manufacturing, fabrication and installation.

This document defines a standard operating system interface and environment, including a command interpreter (or “shell”), and common utility programs to support applications portability at the source code level. This document is intended to be used by both application developers and system implementors and comprises four major components (each in an associated volume): General terms, concepts, and interfaces common to all volumes of this standard, including utility conventions and C-language header definitions, are included in the Base Definitions volume. Definitions for system service functions and subroutines, language-specific system services for the C programming language, function issues, including portability, error handling, and error recovery, are included in the System Interfaces volume. Definitions for a standard source code-level interface to command interpretation services (a “shell”) and common utility programs for application programs are included in the Shell and Utilities volume. Extended rationale that did not fit well into the rest of the document structure, which contains historical information concerning the contents of this document and why features were included or discarded by the standard developers, is included in the Rationale (Informative) volume. The following areas are outside the scope of this document: Graphics interfaces Database management system interfaces Record I/O considerations Object or binary code portability System configuration and resource availability This document describes the external characteristics and facilities that are of importance to application developers, rather than the internal construction techniques employed to achieve these capabilities. Special emphasis is placed on those functions and facilities that are needed in a wide variety of commercial applications.