Books can open new worlds to readers eager to do some armchair traveling. Unfortunately, they can also expose readers to unsavory and vulgar content that sometimes leaps out of dark alleys.

The big problem is in the unexpectedness of the vulgarity; after all, movies, TV shows and video games all have ratings systems that warn about offensive content ahead of time so viewers and users can judge for themselves if they'd like to venture in. There is no industry-sanctioned ratings system for books.

So how is one to find a good book that won't shock? Honestly, it's not easy.

Here are a few clues to help readers discern the potential of a book.

First, if a book's synopsis says it is a "coming of age" story, then a reader can be sure that the book will have sexual content, most likely detailed. If a reader would like to avoid sexual content, avoid "coming of age" plots, hands down.

Second, and possibly obviously, avoid a book that is billed as "edgy" or "raw." Similar adjectives in a book's synopsis or in blurbs usually will indicate content that is unedited in terms of vulgarity, particularly bad language.

Aside from those instances, it's generally difficult to find many clues on a book's cover. There are a couple of other methods that may or may not work.

Sticking with one trusted author works much of the time, but sometimes it doesn't. There's no guarantee one author will choose to write consistently without too much bad language or detailed sex scenes.

Two examples will serve: Carlos Ruiz Zafon, for instance, wrote a really engaging first novel, "The Shadow of the Wind," which, in terms of offensive content, has a dozen uses of strong language and other moderate and mild language. But his second novel, "The Angel's Game," has just one use of strong language and fewer uses of other language. Audrey Niffenegger, who wrote lots of very explicit sexual content into her very popular first novel, "The Time Traveler's Wife," came back with a second book, "Her Fearful Symmetry," that had just a few uses of strong language and only a few milder sexual references.

Another way to learn more about a book before just plunging into it is by word of mouth. This can include asking friends about their recommendations, and searching for reviews and articles about particular books.

In getting more information on the Stieg Larsson series of mystery books that are very popular right now, which start with "The Girl with the Dragon Tattoo," I started asking around. Someone sent a link to a fine article that talked about the book's (and movie version's) overall misogyny and detailed abuse, rape, extreme violence and other very harsh content. It was very useful to finally read something about the book's content other than rave reviews about the story, plot or writing style.

It's also possible to do some judging once one has started reading a book. If there are any uses of strong language in the first 20 pages or so, it's generally going to be a bad sign that there are more to come throughout the book. There are a few exceptions; Some books only have one use of strong language in the whole book, and it might be in the first third. But generally, if there is any near the beginning, it really is just the beginning of language use. The same tends to go for sexual content or other vulgarity.

Overall, just as with movies or TV shows, don't be afraid to walk away. In a movie theater, one can stand up and walk out. With a TV show, all one has to do is change the channel or turn off the set. With reading, it's as simple as closing the book. Snap it shut and take it back to the library, or, if you happen to own it, donate or sell it. Most likely, you won't regret it.

Cathy Carmode Lim is the founder of the website Rated Reads and it's online at