Yes, we use them. We use them on siteplans, to clear out info below the buildings. We also use them on Handrails, so we can "hide" all the linework behind the rails with out trimming out the drawings. And last but not least, we have wipeout frames incoperated into all of our tags, so that we can drop a tag over hatch and have a readable tag without having to re-hatch. I had also noticed that mask is now a dimvar in 2006.