Return Code = 0. What does that mean?

[Qoyyuum Kadir]

As long as the Return Code is not 10009, I can safely assume its an error but looking up on the list of return code here: https://www.mql5.com/en/docs/constants/errorswarnings/enum_trade_return_codes I couldn't find anything for 0.

Here's a sample of the order check result:

OrderCheckResult(retcode=0, balance=84.74, equity=84.74, profit=0.0, margin=1.13, margin_free=83.61, margin_level=7499.115044247787, comment='Done', request=TradeRequest(action=1, magic=20210927, order=0, symbol='USDCAD#', volume=0.01, price=1.27509, stoplimit=0.0, sl=0.0, tp=1.2742049881867534, deviation=20, type=1, type_filling=1, type_time=1, expiration=0, comment='Trading Bot v8', position=0, position_by=0))