/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"

 /NESTED_INCLUDE_DIRECTORY has the following options:

 PRIMARY_FILE   Directs the compiler to search the default file type
                for headers using the context of the primary source
                file (the .C file).  This means that just 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_FILE   Directs the compiler to search the directory
                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.

 See also /INCLUDE_DIRECTORY.