how to switch off warning clutter from conditional compilation when checking standard

Hi

This program:

program test
  !DIR$ if Defined (bla)
  !DIR$ end if
end program test

when compiled with ifort 17.07:

ifort -stand f08 tmp1.f90

yields:

tmp1.f90(2): warning #7025: This directive is not standard F2008.
  !DIR$ if Defined (bla)
--------^
tmp1.f90(3): warning #7025: This directive is not standard F2008.
  !DIR$ end if
--------^

For the example this is a minor problem, but when compiling +100,000 lines of code it can be become very anying when trying to find dangerous standard violations.

Is there any way to switch that off and still check the code for following the standard??

Thanks

Karl