Yolande is the word you say when something unbelievable or unusual has happened. For instance, if that guy who always calls in sick on a Monday, actually turns up on time, everyone in the office will shout Yolande!
It comes from the Eastenders meme when Patrick falls over in the shop out of shock and probably shouts Yolande!
Scott: Nick was out drinking at the weekend he won't be in today.
8.25am Nick walks through the door.
Scott, Dan and Jamie all shout: Yolande!