On my last couple of trips to Vegas, I've seen something that I thought was very odd. There was more than once that someone came to a BJ table, placed a BS card on the table in front of them and referred to the card as they played. Now, it has been happening for quite a while that dealers have been helpful by telling what you should do according to "the books" i.e. split, DD, stand, etc. if you ask them. I could not at the time say for sure that they were giving correct advice (since I was a recreational player who only played adhering loosely to my understanding of BS from experience) but they didn't seem to mind at all offering advice. But it was really surprising to me that they allowed someone to actually play with a BS card in front of them. I thought the casinos frowned on any player aids that lower the house advantage.
I'm not sure what this actually means since if you are a really good player you should have BS ingrained to the point of it being second nature anyway. It was just really interesting to me that they allowed players to play with the cards in front of them.