ISO/IEC 1539-1:2023

Overview

ISO/IEC 1539-1:2023 - Programming languages - Fortran - Part 1: Base language - is the fifth-edition international standard that defines the core syntax, semantics, and conformance rules of the Fortran base language. The document specifies the lexical form, program and execution concepts, data types (intrinsic and derived), attribute declarations, storage and usage rules, and compatibility guidance with earlier Fortran releases. It is the authoritative reference for implementing, verifying, and using Fortran-language features in a standards-compliant way.