1.  Limit Order
For a sell limit order, the order will be rejected if the limit price is higher than twice or lower than half of the best bid price.

For a buy limit order, the order will be rejected if the limit price is higher than twice or lower than 
half of the best ask price.

For Example:
Assuming that the current best bid price of BTC is 20,000 USDT, for a sell limit order, the order price cannot be higher than 40,000 USDT or lower than 10,000 USDT. Otherwise, the order will be rejected.

 

2.  Stop-Limit Order
A.  For a buy stop limit order, the following requirements must be met:
      a.   Stop price ≥current market price 
      b.   The limit price cannot be higher than twice or lower than half of the stop price.
             Otherwise, the order will be rejected

B.  For a sell stop limit order, the following requirements met be met:
      a.   Stop price ≤current market price 
      b.   The limit price cannot be higher than twice or lower than half of the stop price.
             Otherwise, the order will be rejected

Example 1:
Assuming that the current market price of BTC is 20,000 USD, for a buy stop-limit order, the stop price must be higher than 20,000 USDT. If the stop price is set to be 30,0000 USDT, then the limit price cannot be higher than 60,000 USDT or lower than 15,000 USDT. 

Example 2:
Assuming that the current market price of BTC is 20,000 USDT, for a sell stop-limit order, the stop price must be lower than 20,000 USDT. If the stop price is set to be 10,0000 USDT, then the limit price cannot be higher than 20,000 USDT or lower than 5,000 USDT. 

Note: Existing orders on the order books are not subject to the above restriction update and will not be canceled due to market price movement.Limit Price Restriction