A friend used to engrave his name and phone or social security number on things he owned. He painted tools with yellow, clearly marking them. He lent things out and these markings increased the odds of them being returned. Hard to miss the yellow shovel handle.
His Aunt used to have her name engraved on jewelry and mementos bought during her travels. I doubt she lent those things out; yet her items—inherited after her death—are almost all engraved with her initials or her full name, carefully etched, sometimes in tiny letters.
I wonder if it was a family thing?
Or do we humans simply want to make sure our possessions are clearly identified—mine! —and we creatively come up with different ways to do it?