I just love that little five-pointed star symbol. I also like labeling formulas with playing card suits. I think they are easier for the reader to distinguish

I just love that little five-pointed star symbol. I also like labeling formulas with playing card suits. I think they are easier for the reader to distinguish when they are looking back for the labeled formula. A while back I had the idea of marking erroneous formulas with a red spade. I'm going to try doing that again because it's hilarious.