What size was the person's wedding ring? What was the inscription?

Does he have a pacemaker? A lodged bullet? Shrapnel?

Does she have artificial fingernails?

What color did she paint her toenails?

The relatives are also being asked to collect hair brushes, toothbrushes and other personal items belonging to the missing person -- anything that might contain a tiny bit of DNA that can be matched against a body, or part of a body.

Identifying the remains is expected to take months. The task -- overseen by the city medical examiner's office -- will probably be the biggest identification project ever for a group of people killed at one time, said Dr. Michael Baden, chief forensic pathologist for the New York State Police.

Yet Baden, who is not yet involved in the effort, believes that in the end, "every body or part of a body that's recovered should be identified."

"It isn't as overwhelming as it sounds," Baden said. "The bodies are going to be coming up a little bit at a time. It's not a thousand bodies at one time. Bodies will still be there, probably, come Christmas."

Still, the magnitude of the task is daunting.

On Thursday, more than 48 hours after two airliners smashed into the twin 110-story towers, no one knew exactly how many bodies were hidden in the rubble. But Mayor Rudolph Giuliani said 4,763 people had been reported missing, and the city had some 30,000 body bags available to hold the pieces taken from the ruins.

The city's primary morgue can hold several hundred bodies, and a backup morgue capable of holding thousands more was being set up in a hangar at LaGuardia Airport. A Brooks Brothers store near the Trade Center was used at first as a place to store the remains.

Already, the medical examiner's DNA lab has begun turning out DNA profiles from some of the remains. Those profiles could be used to match up body parts, each of which arrives at the morgue in a separate bag with its own number.

DNA can also be used for identifying remains when no answer comes from faster methods of identification, such as fingerprints, dental records, surgical scars and old X-rays.

Information on each person reported missing is being entered into a database. And the city is being aided by teams of experts from elsewhere around the country who are called to disasters by the federal government.

One such expert, Dr. Richard Weems, a forensic dentist at the University of Alabama at Birmingham, received word Tuesday to get packed and await orders to fly to New York.

Dental identification is a powerful tool, good enough that a single tooth can do the job, Weems said. The tip-off is usually not teeth themselves, but manmade additions: fillings, crowns, bridges, implants. A single filling can have a distinctive enough shape that it can be matched to a person's dental X-rays.

Other X-rays from a person's medical files can also help. An X-ray can show the distinctive shapes of bones that can be matched to a body.

But if all else fails, there is DNA. Invisible traces of the stuff -- from a licked envelope, a T-shirt or underwear -- can be enough to produce a distinctive DNA profile, said Bob Shaler, director of the medical examiner's DNA lab.

One of the victims of TWA Flight 800, which crashed off Long Island in 1996, was identified by way of DNA taken from his toothbrush at home.

Shaler said he doubts everybody who perished in the attacks will be identified, simply because some remains will never be found. But "if we're lucky enough to find the pieces from everybody," he said, "we have a shot at it."

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