The best written works contain clarity, consistency and elegance. These are the goals of style books.
My first AP Stylebook was a 1976 edition acquired in 1979 when I started high school. I read every entry. I didn’t memorize it, but I at least knew where to look up whatever question I had. Over time, my knowledge of the book diminished rather than increased, but nowadays my online subscription means searching is just as fast as it was when I was 15.
Jojo Malig, an editor in Manilla, Philippines, wrote a column for the Poynter Institute’s website in which he asked several editors about the necessity of multiple style books, such as the Chicago Manual of Style and house style guides. I suggested that local style guides are an important supplement to the AP Stylebook or whatever style book a publication uses as its main guide.