Here's what I did, somebody please talk me out of it...

Client received a 1099B for a regulated futures contract with only box 9 and box 11 completed (other than box 1a "description"). Box 9 is positive and box 11 is the same number only negative. For example Box 9 is $1,234 and box 11 is ($1,234). 

In the Contracts & Straddles (6781) section, I put box 11 in "section 1256 contracts gain (loss)" and box 9 in "Unrecognized gain on offsetting positions (straddles)". I then selected "2=straddles". 

As I understand it, this 1099-B is reporting the loss (box 11) from the closed contracts for the year that correspond to the unrealized profit from the previous year. My client's 2017 1099-B shows the same $1,234 in box 10 (unrealized profit).

At first glance, this appears to be a wash, but I know this isn't the case. Any profit or loss realized is reported in the tax year, then it's offsetting leg to the straddle is reported when it is realized, thus causing the odd looking 1099-B. 

If I've gotten this wrong, then I would appreciate some feedback. Feel free to troll me if you wish 😉 Seriously, I welcome any and all criticism.

Thanks!