/NESTED_INCLUDE_DIRECTORY
       /NESTED_INCLUDE_DIRECTORY[=option]
       /NESTED_INCLUDE_DIRECTORY=INCLUDE_FILE (D)

    Controls the first step in the search algorithm the compiler
    uses when looking for files included using the quoted form of
    the #include preprocessing directive: #include "file-spec" The
    /NESTED_INCLUDE_DIRECTORY qualifier has the following options:

    Option     Usage

    PRIMARY_   Directs the compiler to search the default file type
    FILE       for headers using the context of the primary source
               file. This means that only the file type (".H" or ".")
               is used for the default file-spec but, in addition,
               the chain of "related file-specs" used to maintain
               the sticky defaults for processing the next top-level
               source file is applied when searching for the include
               file.
    INCLUDE_   Directs the compiler to search the directory
    FILE       containing the file in which the #include directive
               itself occurred. The meaning of "directory containing"
               is: the RMS "resultant string" obtained when the file
               in which the #include occurred was opened, except that
               the filename and subsequent components are replaced
               by the default file type for headers (".H", or just
               "." if /ASSUME=NOHEADER_TYPE_DEFAULT is in effect).
               The "resultant string" will not have translated any
               concealed device logical.
    NONE       Directs the compiler to skip the first step of
               processing #include "file.h" directives. The compiler
               starts its search for the include file in the
               /INCLUDE_DIRECTORY directories.

    For more information on the search order for included files, see
    the /INCLUDE_DIRECTORY qualifier.