Limit-On-Close Order - LOC
  
See: Limit Order.
Broadly speaking, a limit order lets traders map out a pre-set buy or sell order for a stock (or other exchange-traded asset). You might set your limit order to buy 500 shares of NFLX stock at $350. Then the order sits there, waiting for the stock to reach that level.
A limit-on-close order represents a specific kind of limit order. It only executes at the close of trading, based on the market price for the stock at the end of the trading session.