There have been a few times my UQ has moved on me during the night, and you find a portion of your body being exposed because the UQ is no longer covering that part of you. I'm thinking of positioning my UQ to its best placed position and sewing buttons on each corner of my UQ and sewing shockcord loops on to my hammock. The shock cord would secure the buttons, but not too tighly, there by giving slight movement but also restricting the UQ's movement for total slippage. (I don't plan on removing the shockcords from the channels, nor the foot and head drawcords). The buttons would only supplement them. I saw Dutch's quilt clips which I did like, but I believe the buttons would not allow for any sliding lateral movement at all.