The best way would be asking the signal provider. The second way is to check the trade history, if you can: maybe you can ask the provider for a statement. In my opinion, NFA rules are ludicrous and designed to limit the adaptability to the market a retail trader can have. You can't trade grids for example, but banks can trade grids against you! In facts banks use grids all the time. When it comes to trading, those participants with higher adaptability usually win. I warmly recommend you to look for a NON-FDA broker, outside the US. Some regulations accept US clients, like the Maltese for example. Hope this helps.
It's interesting, but can you please explain why "banks can trade grids against you" ? The NFA rules doesn't apply to banks ?
And also can you give for information about "banks use grids all the time" ?