What does "to prevent trade busts for executions away from market your order has been rejected" mean?

You are attempting to add an order for a contract where an open order already exists on the opposite side of the market. Customers are prevented, by regulation, from entering a buy and a sell order for the same option contract. The right to be on both sides of the market is reserved for market makers…

A Reference Price is used when calculating the allowable order prices that can be submitted within the active Price Bands for a contract. The Reference Price may be the current Mark Price, the Close Price or a Theoretical Price that is used to create the current upper and lower limits of a Price Band.  Any order submitted with a price above or below the current Price Bands would not be accepted. Price Bands can be calculated dynamically or by using a set amount from the Reference Price. As an example, if the current Reference Price is using a Mark Price of 10.00 and the current allowable price for a sell order cannot be placed more than 18 % below 10.00, then any sell order submitted at or below 8.20 would not be accepted. If your order is not accepted due to a price that is considered too far from a Reference Price, you may try to recreate and resubmit a new order at a price within the current allowable price limits.  …

A Market order is an order to buy or sell at the market bid or offer price. A market order may increase the likelihood of a fill and the speed of execution, but unlike a Limit order, a Market order provides no price protection and may fill at a price far lower/higher than the current displayed bid/ask…

You can trade cryptocurrencies only using Market or Limit orders. Market orders can be submitted in cash value only (e.g. $10,000 worth of BTC). Limit orders can be submitted in either trade value or quantity terms, but the entered trade value will be converted to quantity and transmitted to OSL in quantity terms. A Limit order is an order to buy or sell at a specified price or better. The Limit order ensures that if the order fills, it will not fill at a price less favorable than the limit price, but it does not guarantee a fill…