The numbers are preceded by words like AD and BR. The meanings of these prefixes are:

(1) AD=Adult Directed parent guidance books. This type of reading material is generally a picture book with text, which is suitable for parents to read with their preschool children.

(2) NC=Non-Conforming unconventional books. The language difficulty of this type of reading material generally exceeds the reading ability of the target readers. Suitable for readers with above average reading ability.

(3) HL=High-Low books with high interest but low difficulty. Suitable for students with lower reading ability in higher grades.

(4) IG=Illustrated Guide emoticon. Usually an encyclopedia.

(5)GN=Graphic Novel comics or comics.

(6) BR=Beginning Reading. This type of reading material for young children usually has less text and cannot give a specific Lexile level value.

(7) NP=Non-Prose prose articles. Such as poetry, lyrics or recipes.

This type of article cannot be used to assess Lens grade