These are the Things that Make a Man
Iron enough to make a nail,
Lime enough to paint a wall,
Water enough to drown a dog,
Sulphur enough to stop the fleas,
Potash enough to wash a shirt,
Gold enough to buy a bean,
Silver enough to coat a pin,
Lead enough to ballast a bird,
Phosphor enough to light the town,
Poison enough to kill a cow,
Strength enough to build a home,
Time enough to hold a child,
Love enough to break a heart.
Terry Pratchett, Wintersmith
This source says cats can’t see them.
https://www.sciencealert.com/humans-actually-have-secret-stripes-and-other-strange-markings
I have no idea if sciencealert.com is reliable.