== Categorization is for defining characteristics == 

 You have been adding left-handed categories today. I saw you put one in at Harry S. Truman. I took a quick look at the various biographies and none of them says that Truman's left-handedness was important. At WP:Categorization, the instructions say that a category should be a defining characteristic, not a trivial one. Please keep the instructions in mind as you add categories. Thank you.