Use a source code directive, a form of Fortran comment, to pass specific information to the compiler regarding special optimization or parallelization choices. Compiler directives are also sometimes called pragmas. The compiler recognizes a set of general directives and parallelization directives, including OpenMP directives.
Directives unique to f95 are described in Directives. A complete summary of all the directives recognized by f95 appears in Appendix C, Fortran Directives Summary.