"don't pick a bike if its seat is twisted around backwards. That's a sign that a previous rider found the bike busted." -(from SamtheBrand's answer to How to choose the right Citi Bike? )
Can someone please elaborate on this rule please?
Is it widely known and used?
Is this some sort of official or unofficial rule communicated somewhere?
Is it specific to Citi Bike program or generic to any bike rental/sharing ones?
 - I have ridden Citibikes almost every weekday for over a month in NYC, and have never observed a twisted-around seat. But I didn't set out to find one so it's not much of an evidence.