Do you want to put your phone on the do-not-call list or stop credit card companies from soliciting consumers or end the flow of junk mail and catalogs? Opting-out can have the side effect of protecting personal information that can be misused by identity thieves or unscrupulous merchants. 

PHONE SOLICITATIONS To stop them, go to www.donotcall.gov. Or call toll free, (888)382-1222, from the number you are going to restrict. A listing is good for five years, after which you’ll have to repeat the process. 

JUNK MAIL A private organization, the www.the-dma.org/, handles the list of direct mail solicitations, and not every merchant is a rule-abiding member. You can write the association, in care of the Mail Preference Service at P.O. Box 643, Carmel, N.Y. 10512, or use the online form at www.the-dma.org/consumers/offmailinglist.html. 

E-MAIL Do not respond to an unsolicited e-mail message when it gives you the option to opt out of receiving more e-mail. That is a trick used by spammers to confirm they hit a live address. You can try to make it harder for spammers to get your address in the first place by never posting your address in public forums. Spammers employ software to scrape the sites of anything with that @ symbol. Instead spell it out in a unique way like “YourEmailName at company.com.” 

CREDIT CARD OFFERS Call (888) 567-8688, but be ready to give out some personal information like your Social Security number. The major credit bureaus, like Experian, Equifax and TransUnion, that collect information on your borrowing habits, let you opt out of what they call prescreened offers of credit at https://www.optoutprescreen.com. You can do it for a period of five years or permanently. Use a paper shredder on the credit card offers you do reject. 

CREDIT FREEZE The ultimate opt-out for your credit is a credit freeze. No company can get access to your credit report without your expressed permission. No one can open up a credit card or take out a loan in your name (including you, while you have a credit freeze). Use the credit freeze only if you are a true victim of identity theft, which means that some criminal has your personal information and is opening up credit card accounts, borrowing money or buying property with your credit history. If you suspect you may be a target, but have not been harmed yet, a better form of protection is asking the credit bureaus to flag your report with a fraud alert, which is supposed to make lenders take extra precautions. 

ONLINE computer internet tracking. DoubleClick, a company that collects data for online advertisers, offers a way to prevent your computer from giving it information at http://www.doubleclick.com/us/about-doubleclick/privacy/dart-adserving.asp. Frequently run software that cleans out cookies. You can get Spyware Blaster, Spybot, or Ad-Aware at www.download.com free. 

DATA BASES  Nexis, one of the biggest publicly available data bases, says you can opt out of its people-finding lists by going to www.lexisnexis.com/terms/privacy/data/remove.asp. Nexis does not make it easy because it requires that you prove you are a victim of identity theft before it will consider your application. 

The Center for Democracy and Technology provides addresses and forms for other companies that do not let you opt out online (http://opt-out.cdt.org).