Like any other new technology, instant messaging (IM) is evolving its own rules of engagement -- especially in business. Here are some tips for using IM wisely at work:

Consider the content: IM works best for quick questions, updates, and schedule changes. For complicated or critical messages, send an E-mail, pick up the phone, or hike down the hall.

Be brief: Keep messages almost telegraphic -- no more than a sentence or two. Save longer conversations for meetings and conference calls.

Be kind: Never deliver bad news or major announcements by IM; the format will seem to trivialize the message.

Be smart: Don't use IM to negotiate contracts, place orders, or make personnel assignments. Put those things in writing, preferably with a fax or a letter.

Be careful: Never include sensitive or confidential information in a message. It's too easy for someone to cut and paste the text into an E-mail or another document that might be passed on.

Knock first: Open every message by asking whether you're interrupting ("Is this a good time to talk about Davis?"). On your end, learn to say no when you're busy: "Can't now, how about at 2?" or "Later, OK?"

Try the tools: Many IM programs have icons that you can set to indicate your status: available, on the phone, do not disturb, away. Use them.

Keep it professional: Limit the use of cutesy, potentially confusing acronyms and slang -- "G2G" for "got to go," for instance. And pick an appropriate screen ID. As one CEO observes, "Monkeyboy42 is probably not a good business IM name."