Mind your manners, the modern way

A customer recently went to an independent bookstore and asked the clerk whether a certain title was available. "I've looked at Amazon," he said, "and iBooks and -- oh, sorry."

"It's OK," the merchant replied about the online sellers that are putting many stores out of business. "We get that all the time."

Welcome to today's fast-changing world of etiquette. Technology has broadened our potential for gaffes:

• Snarky e-mails in which you accidentally hit "reply all" and include the target of your derision.

• An embarrassing Facebook photo posted by (someone you thought was) a friend.

• An auto-correct feature turning an innocuous text message into X-rated material.

It's no surprise, then, that "How to Behave: A Guide to Modern Manners" (Quirk, $15) includes "While in Cyberspace" among its seven chapters. Caroline Tiger's book, out Tuesday, also addresses such quandaries as who gets the armrest in seriously cramped airplane seats (one per person) and how to deal with the bozo who tries to cart 22 items through a "10 or fewer items" grocery-checkout lane (discreetly point it out directly, then count out loud).

Some of the Web-focused tips seem obvious: "[No Facebook posts on] granular info about sex lives or bowel movements." Also: "If you do comment [on blogs], don't do so anonymously, especially if what you have to say is nasty. ... As a general rule, don't say anything in a comment that you wouldn't say to the person's face."

Others are more nuanced: "Don't use any social networking account solely as a venue for self-promotion. Even if the page is explicitly for your company or business, your ratio of community-building to promoting should be about 80 to 20."

Still, it's a challenge to give Web-related advice in a book because, she said, "cyberspace is changing and evolving so fast, so something in a book might be out of date quickly."

The toughest digital arena, Tiger said, is what level of formality to use in e-mails for the people in different relationships in your life -- "because there are no real rules."