Update README.md

README.md

@@ -19,7 +19,7 @@ All relevant publications regarding the model see the directory publications.
 
 The source code is distributed via a git repository at: 
 https://gitlab.pik-potsdam.de/foresee/4C
-The code language is Fortran and is ready to use. Since the model development is
+The code language is Fortran90 and is ready to use. Since the model development is
 finished, there is no further development and no further support in model 
 download, setup, development or application. No merge or other development 
 requests will be handeled. There fore there are no code style recommendations or