The OpenMP API defines constructs that operate in the context of the base language that is supported by an implementation. If the implementation of the base language does not support a language construct that appears in this document, a compliant OpenMP implementation is not required to support it, with the exception that for Fortran, the implementation must allow case insensitivity for directive and API routines names, and must allow identifiers of more than six characters. An implementation of the OpenMP API is compliant if and only if it compiles and executes all other conforming programs, and supports the tool interfaces, according to the syntax and semantics laid out in Chapters 1 through 20. Appendices A and B as well as sections designated as Notes (see Section 1.8) are for information purposes only and are not part of the specification.
All library, intrinsic and built-in routines provided by the base language must be thread-safe in a compliant implementation. In addition, the implementation of the base language must also be thread-safe. For example, ALLOCATE and DEALLOCATE statements must be thread-safe in Fortran. Unsynchronized concurrent use of such routines by different threads must produce correct results (although not necessarily the same as serial execution results, as in the case of random number generation routines).
Starting with Fortran 90, variables with explicit initialization have the SAVE attribute implicitly. This is not the case in Fortran 77. However, a compliant OpenMP Fortran implementation must give such a variable the SAVE attribute, regardless of the underlying base language version.
Chapter A lists certain aspects of the OpenMP API that are implementation defined. A compliant implementation must define and document its behavior for each of the items in Chapter A.