Babypips school error

on this page
Margin Defined | College: The Number One Cause of Death for Forex Traders | Learn Forex Trading

last bit:
Margin call: If the equity in the account drops below your [B]usable[/B] margin, a margin call will occur and some or all open positions will be closed by the dealing desk at the market price.

should that not be [B]used[/B] margin?

No. Margin calls are based on your maintenance margin level, which is usually 50% of your initial margin.

no it’s right the way it is

there is a difference between used margin and usable, if your usable falls to $0 then you get a margin call.

ok I am confused…

The very next page of the schools
Margin Call Example | College: The Number One Cause of Death for Forex Traders | Learn Forex Trading
says
( Equity =< Used Margin ) = MARGIN CALL, go back to demo trading

so which one is right? They both can’t be right? my poor brain…

I wasn’t confused before but now I am. Any gurus care to straighten this out for me (us). lol

PS - Babypips rules !!!

Read Oanda’s explanation. It will probably help.
Margin Calculations | OANDA FXTrade