When all  else fails, look at the instructions that come with the 1099-B

and DO YOU KNOW WHAT IS MORE ANNOYING THAN USING ALL CAPS?

Box13.Showsthecashyoureceived,thefairmarketvalueofanypropertyorservicesyoureceived,andthefairmarketvalueofanytradecreditsorscripcreditedtoyouraccountbyabarterexchange.SeePub.525.