Message This declaration of "<name>" specifies a different type than the declaration in another module of this compilation at <where>. Description In a compilation where interfile optimization has been selected (-ifo on UNIX, /PLUS_LIST_OPTIMIZE on OpenVMS), the compiler has detected a name with external linkage declared with different types in two different modules. Although the runtime behavior may be as intended and match the behavior when the modules are separately compiled without interfile optimization, the behavior is not well defined unless the types are compatible. User Action Modify one or more of the declarations to make the types compatible.