percentage of that then has to be either sand blasted, or have like little dots on it, like the floors at niketown at union square, when you walk on it, it has raised dots so that you aren't skidding. >> that's a requirement primarily in the disabled access regulations of chapter 11 of the california building code and national ada requirements, which gives it a index of -- what is it called? slip resistant index, coefficient of friction. that's in a path of travel open to the public. there would not be a requirement for slip resistance in a private dwelling. >> the good news is that there's a new product, which is totally, totally clear, and it's slip resistant. it's like a coating that goes on, you don't know it's there, so the glass can remain totally clear, and you can walk on it, but you don't slip. >> do you have to reapply it? >> no. >> the reapplication is a problem. so when they opened the san francisco center, nordstro nordstrom's downtown, they have ramps on the ground floor, very gentle ramps but highly polish polished. the inspector said this is a slipping hazard and they said we will