2 More Noticeably Different Signs

My family and I volunteered to serve on the "clean up" crew at the Topeka Dog Show this week. Events like this always provide at least a couple of examples of signs trying to dictate behavior. These two signs posted at the Topeka Expo Center caught my eye, so I added them to the collection of noticeably different signs.

THE BIG NO > there was an entire room dedicated to crating and grooming animals, so in the main arena they had these signs posted about every 10-15 feet. I love when the signs so clearly get ignored.

CAUSE AND EFFECT > I'm very curious about what problems they were having in this room. Taped on this very plain, not inviting door was this sign of three "no"s. I can figure out the "no admittance" and "no knocking," but what are they trying to prevent with "no change." Do they not want to give change for a dollar? Or do they want to stop people from changing their outfits? Or are they just adamant about things staying the same?