The use of graffiti as a source of data has spread beyond studies of human sexuality and urban youth to include linguistic studies of discourse patterns and grammar, explorations of cultural production in disputed areas, and modeling gender differences. While many of these studies focus on latrinalia, graffiti written in bathrooms, two recent papers have documented and classified graffiti in a defined subset of public areas at a single university. This work builds upon those studies by documenting and classifying graffiti in the main library of four universities in the United States: the University of Chicago, Brown University, the University of Colorado at Boulder, and Arizona State University. A quantitative analysis suggests that insults and remarks about advice, classes, love, the surroundings, school, and oneself should be considered common in graffiti found in university libraries, in addition to sex. A qualitative analysis explores the trends in writing style and approach to the various topics in each corpus.