About margin calculations

 

hello,

here are some values i dont understand about margin calculations in different instruments, (which is shown at  https://www.mql5.com/en/docs/constants/environment_state/marketinfoconstants#enum_symbol_calc_mode)

as in SYMBOL_CALC_MODE_CFDLEVERAGE  -> Margin = (Lots*ContractSize*MarketPrice*Percentage)/Leverage,  

what exactly is the 'Percentage' here. percentage of what? is it a return value of a function? or we set it?

can someone explain please..