Resharper.CleanupOnSave is a Visual Studio Extension that calls ReSharper's Silent Cleanup Code command when you save your solution.
It is based on this extension.
Allowed File Extensions
If you don't want to execute the command for a specific file extension, you can change the allowed file extensions.
To do this you have to open Tools->Options and go to the category ReSharper.CleanupOnSave. Under Allowed File Extensions you can now disallow a specific file extension by setting it's value to false.
