I never attached the forum to my tax returns and I don't think I received any notice from the IRS. Since I was new to trading, I had no idea that everything you make or lose is supposed to be reported. I was under the impression if you gained a large amount of capital you would need to report that. The 1099 B didn't exist until yesterday for me. I had no idea it was a thing nor that I needed to include it in my tax returns. With that said, the cost basis is under A on my forum.
