A G-rated book contains nothing in theme, language, nudity, sex, violence or other matters that, in the view of the reviewers, would offend the readers. The G rating is not a "certificate of approval," nor does it signify an immature or easy read. Some snippets of language may go beyond polite conversation but they are common everyday expressions. No stronger words are present in G-rated books. Depictions of violence are minimal. No nudity, sex scenes or drug use are present in the books.

A PG-rated book should be reviewed before younger readers select the title. The PG rating indicates, in the view of the reviewers, that material may be unsuitable for younger readers, and they should exercise caution. The more mature themes in some PG-rated books may call for discretion. There may be some profanity and some depictions of violence or brief nudity. But these elements are not deemed so intense as to require that readers be strongly cautioned beyond discernment. There is no drug use content in a PG-rated book. There can, however, be a mention of a drug.  No more than ten expletives, mild innuendo, or mild crude humor will be present in these books. 

A PG-13 rating is a sterner warning by the reviewers to readers to determine whether they should read the book if they are under thirteen, as some material might not be suited for them. A PG-13 book may go beyond the PG rating in theme, violence, nudity, sensuality, language, adult activities or other elements, but does not reach the restricted R category. The theme of the book by itself will not result in a rating greater than PG-13, although depictions of activities related to a mature theme may result in a restricted rating for the book. Any drug use will initially require at least a PG-13 rating. More than brief nudity will require at least a PG-13 rating.  There may be depictions of violence in a PG-13 book, but generally not both realistic and extreme or persistent violence. A book's single use of one of the harsher sexually-derived words, though only as an expletive, initially requires at least a PG-13 rating.  More than one such expletive requires an R rating.  A PG-13 book will contain no more than forty expletives, moderate drug abuse, or moderate sex.

An R-rated book, in the view of the reviewers, contains some adult material. An R-rated book may include adult themes, adult activity, strong language, intense or persistent violence, sexually-oriented nudity, drug abuse or other elements, so that readers are counseled to take this rating very seriously.  Readers are strongly urged to find out more about R-rated books in determining their suitability for entertainment. R-rated books will contain no more than seventy expletives, lewd sex, graphic drug abuse, or persisting and graphic violence.

An NC-17 rated book is one that, in the view of the reviewers, most parents would consider patently too adult for teens 17 and under. The rating signals that the content is appropriate only for an adult audience. An NC-17 rating can be based on violence, sex, aberrational behavior, drug abuse or any other element that most parents would consider too strong and therefore off-limits for reading by teens.  NC-17 books will contain more than sixty expletives, persisting and graphic sexuality, or constant, graphic, and vulgar violence.