I understand it this way:
SQP ( Squeeze protection price) is 10%, force buying back discount range.
At 175% collateral x 1.1(SQP) =192% to feed price, marging call trigers buying back in 175-192% range, meaning, if for instance in bitBTC market:
BTS/bitBTC feed price is 250,000 or bitBTC/BTS is 0.00000400, everyone who owns 1 bitBTC needs to lock 250,000x192%=480,000 colateral.
If it doesn't have enough , then it is forced to buy back bitBTC in price range of 1.1x250,000=275,000 - 250,000 BTS/bitBTC
or 0.000003636-0.00000400 bitBTC/BTS price range.
As feed price moves down, SQP moves with it through order book.