What does a blue reflector (cat's eye) placed on the road mean?

What does a blue reflector (cat's eye) placed on the road mean?undefined
No passing
A fire hydrant nearby
Blue marks the left side of the road
Blue marks the middle line
It's safe to pass here

There is a fire hydrant nearby, so be careful when choosing a parking spot. Remember: white reflective markers (cat's eyes) appear in the center of the road, indicating the middle of the road. Yellow reflective markers (cat's eyes) are equivalent to a solid yellow line, which indicates that overtaking is prohibited.