Mine are Rancho, they are slit, and if you look carefully you can see the zip tie tails sticking out to the sides; not clipped yet.  

Update.  I did cut off the slit section end and the other end collar is too small for the fork tubes, so I trimmed off the inside ridges and used two HD zip ties, and it went all the way around tight.  Push them upwards really firmly against the lower triple as you pull the zip ties tight.  

Tried dabs of super glue to hold the bellows back together, didn't stick so I overlapped them a bit and kept the zip ties around the pleats a bit loose so the bootie will slide up and down without dragging.  

Also added a long zip tie around the bottom pleat and threaded it thru/under the back part of the fork brace to keep the bootie down on the brace.  

Went riding and they stayed in place fine.    Longer narrower zip ties would be nice.  

Happy whatever holiday of your choice this weekend.