When an array is passed as a parameter, the actual and formal arrays must be of compatible data types (such as integer, real, and so on). The actual and formal arrays must also be compatible structurally. That is, the number of dimensions and the lower bounds for each dimension must be compatible.

The following subsections discuss these types of compatibility issues for arrays that are passed in process initiation statements. Note that this discussion centers on the compatibility issues the system enforces at run time. If the parameter is passed between procedures in a single program, the compiler can enforce additional restrictions at compile time. For information about any such compile-time restrictions, refer to the appropriate programming language manuals.