I only have my father's explanation of what it means to see (bob-wired) fence posts tops painted purple. As a child riding through the countryside of Texas I often saw these fence posts usually at the corner post. When I asked my dad what it meant he told me. Patches I'm depending … no wait wrong story. What he said was boy those are for people who can't read. The purple fence posts tells the people that can't read that the owner of the property is telling them. This is my property my land YOU are not allowed on it. It means Posted No Trespassing