the IRS says that's where they go unless you are a trader. then they go on schedule C.
for investors
If, while holding a short sale, a dividend was issued which ultimately came from your brokerage account, the amount may be able to be deducted as an investment expense on Federal Schedule A (Form 1040
please note that there will be no benfit unless you that itemize deductions and they exceed your standard deduction. any amount unused would be a carryover but only if you itemize.