How to reference an unused parameter?

Maybe the discard _ is what you're looking for:

void Foo(string parameter)
{
   _ = parameter;
}

Using the SuppressMessage attribute you can suppress warnings where ever you want:

[SuppressMessage("Microsoft.Performance", "CA1801:ReviewUnusedParameters", MessageId = "isChecked")]
[SuppressMessage("Microsoft.Performance", "CA1804:RemoveUnusedLocals", MessageId = "fileIdentifier")]
static void FileNode(string name, bool isChecked)
{
   string fileIdentifier = name;
   string fileName = name;
   string version = String.Empty;
}

This also gives the reader an explicit understanding that this is intended behavior.

More on the SuppressMessage attribute.

You can use the following syntax to disable and re-enable specific warnings. Surround the code that declares the unused/unreferenced paramter:

#pragma warning disable <warning-number>

// ... code that declares the unused parameter

#pragma warning restore <warning-number>

Where the <warning-number> above would be the warning number issued by the compiler that you wish to suppress. Presumably that would be C# warning number 219.