which -W option triggers unused variables warning?

[Kamaraju S Kusumanchi]

I am using -Wall option while compiling the code using gfortran 4.2.0 on
CentOS 4 system. However I am getting lot of warnings such as

  real(WP) :: q
              1
Warning: Unused variable q declared at (1)

Can someone tell me

1) which -Wxxxx option triggers this warning?

I looked in the man page of gfortran but that does not mention anything
about warnings on unused variables.

2) Is there any way just to disable this one type of warning and enable all
other warnings?

thanks
raju

-- 
Kamaraju S Kusumanchi
http://www.people.cornell.edu/pages/kk288/
http://malayamaarutham.blogspot.com/