The print page is very helpful. Formats refers only to alphabetical letter divisions and these are not letters. I would treat these as headings, specifically cell-5 for the larger red print and cell-7 for the smaller print. Guide words are optional in an index. See Formats 22.3.2 which states an agency may choose to omit braille guide words in certain alphabetic references such as an index. Personally, Given the nature of this material, I would omit guide words unless requested to include them.