Parameters for Custom BP Function


I have encountered a strange behaviour in the Unreal Engine.
Maybe someone here can explain it to me.

I have two functions as a part of an ActorComponent

	void GenerateTrack(FChunk &chunk);

	UFUNCTION(BlueprintCallable, Category = "WorldChunkManager")
	void RenderChunk(FChunk chunk);

Please note that one is a reference parameter and the other isn’t.

Now, when I access these functions in the BP Editor, I get this

Why is the input parameter of the function with the reference param on the other side?
How can I ever connect that pin as an input?



Here you go: C++ reference parameter is return value in Blueprint - Blueprint - Unreal Engine Forums

Thanks! Such an obscure syntax, hidden away!