Washington --- Two words rally gun owners like nothing else: licensing and registration. 

And with the latest Democratic Party platform endorsing gun control measures, such as child
safety locks and strict background checks, gun owners say they are increasingly worried. 

In the National Rifle Association's July newsletter, the group's president, Charlton Heston, warns:  ''Once some Gore government has the names, addresses, photos and ownership inventories of every gun owner in America, we all know what comes next. Once liberty is transformed into license, that license can be revoked.'' 

Conversely, groups that advocate gun control say that licensing and registration will save lives.  ''(Licensing and registration) would make sure that the wrong people don't get a hold of guns; make sure that people know how to use guns properly; make it easier for police to trace crime guns and detect gun traffickers; and it makes sense,'' said Nancy Hwa, a spokeswoman for Handgun Control Inc., a group that supports gun control. 

Proponents of licensing and registration say it would help weed out criminals who are trying to purchase firearms through legal channels and that it would prevent illegal sales by making the registered owner responsible for what happens to his or her own gun. 

To obtain a license, which includes a photo ID, applicants would have to pass a background check, including a check for violent misdemeanor convictions, domestic violence and mental illness. In addition, the applicant would have to demonstrate knowledge of firearms safety and the laws governing the use, possession, storage and transfer of handguns. 

In the same way people who get driver's licenses must learn how the vehicle works and the laws of the road, people who buy guns should take a safety course and a test to prove that they know how to handle a gun and that they know the rules, Hwa said. 

But gun owners, such as Ken Bagby, say that licensing and registration would burden only law-abiding citizens. 

''The laws that they are creating have nothing to do with stopping crime. It is an issue that deals with the honest citizen who will go register their gun,'' he said. 

Bagby, who lives in Shelby, N.C., and has been a hunter since he was a child, said that charging fees for licensing and registration would discriminate against poor gun owners, who are often the most vulnerable to crime. 

''First it's $25 to register your gun, then it's $50, then it's $200, then it's what have you. . . . If a poor person can't afford that, that's unfair as heck,'' he said.  ''These are people that live on the front line. They're in the housing projects.  They need the protection. The cops won't even go in there sometimes.'' 

The idea of more federal record-keeping also makes gun owners uneasy as many are already skeptical of government and fear that its ultimate goal is to disarm citizens. 

''There's no ifs, ands or buts about it . . . the more information that's there makes it that much easier,'' Bagby said. 

Many gun owners have taken to the Internet to express such fears. Dozens of sites, such as www.thefiringline.com, provide chat rooms and other forums for concerned gun owners to share information. 

''Every gun owner in America gets really angry and activated by this,'' said Josh Sugarmann, executive director of the Violence Policy Center, a Washington-based group that supports the banning of handguns and other gun control measures. 

The intense reaction of the gun lobby to the issue of licensing and registration is one of the reasons his group does not push it as a solution to violence. 

The bigger reason, the group says, is that licensing and registration would have little effect on most U.S. gun violence because most homicides are the result of arguments between people who know each other and who purchase guns legally. 

The focus should be on the product and the manufacturer, not the user, Sugarmann said. 

He cites as an example that licensing and registering of cars had no effect on automobile deaths and injuries. Cars became safer only after the National Highway Traffic and Safety Administration was established and mandated road safety improvements and changes to car designs, he said. 

Opponents to national licensing and registering also say it would be too expensive. 

That's what happened in Canada. 

In Canada, the government originally estimated that licensing and registration of that country's 7 million guns would cost about $185 million Canadian ( $125 million U.S.) over five years. The project, which began in December 1998, has already cost more than $320 million Canadian ($216 million U.S.), according to the Canadian Firearms Centre. 

With an estimated 65 million handguns in the United States, the cost of such a system could be staggering.  But proponents of a national licensing and registration system say that saving lives would offset any price.  

''We definitely think it would be (worth it) compared to the costs of the gun violence that we have in this country --- the economic costs, the human costs and emotional costs,'' Hwa said. 

While licensing and registration of firearms is a major goal for gun control advocates, it has not been on the congressional radar screen. 

The issue is not included in a package of gun control proposals --- currently stuck in Congress --- that includes stricter background checks at gun shows, requiring child safety locks on guns, and banning the import of high-capacity ammunition clips. 

National Rifle Association: www.nra.org