How to find form 7-442 for 1910 census of Christian County, Kentucky

I want to understand the last three columns on the 1910 Census. While searching for Allen Cushenberry on the 1910 census in Christian county, Kentucky, column 30 should have has "UA, UN, CN or be blank, but I found the number 15.  In column 31 I should have found "BL" or blank, but instead I found a large "X". In column 32 I should have found a "DD" or blank, but I found the number "5" instead.  In the far right margin I found a large check which was present for some of the other Black men on the page. Maybe form 7-442 holds the answers, but I'm unable to locate the completed form for 1910 census. Where might I find answers to my questions?  PLEASE help!!!