@jh73
"According to the IRS instructions for Form 8949, Code M means "You report multiple transactions on a single row as described in Exception 2..."
The word "transactions" here is referring to sales and has nothing to do with the "various" notation you're seeing on Form 8949. You have, maybe by mistake, told the IRS "I'm just going to enter lump sums for a whole bunch of trades and I'll send in the detail - sale by sale listing - later." One way or the other you do need to itemize every sale of a noncovered security to the IRS. I'd advise deleting the 1099-B and starting over.
The IRS has, for a long, long time, allowed you to use "various" in the Date Acquired field when you've executed a trade where multiple lots are sold. Your obligation here is to report the trade correctly which comes down to date of sale, proceeds, the "term" of the security sold (long or short) and the basis. In this instance you don't provide support for the term or the cost basis you're reporting for the trade to the IRS.
