WASHINGTON — They are lined up like footnotes to the names etched on the Vietnam Veterans Memorial's polished black granite, leaning against its base, some a collective tribute to the fallen, others bearing a message for just one of the dead.

An American Legion uniform cap from Kansas, a police patch from a town in Georgia, a note to "GRAMDADAD" that appears to have been written by the unpracticed hand of a young child. A homemade plaque with plastic red poppies pasted to it, dedicated to a "Band of Brothers." Poems from middle school students.

"We met once when you played golf with my dad," reads one note, written hastily on a piece of yellow notebook paper, addressed to a Major Shaw. "You served together in Vietnam. He made it back to us. I'm saying goodbye."

Since the memorial was completed in 1982, it has become a de facto shrine with more than 100,000 offerings for the dead and messages from survivors left by the millions who visit it each year.

That number is likely to grow in the coming days. National Park Service officials say milestones like Veterans Day today and the memorial's 25th anniversary on Tuesday inevitably lead to floods of new items at the wall, as veterans gather at the site on the National Mall and the memories of the war that ended more than 30 years ago are renewed.

The nature of the mementos has changed. In the beginning, it was mostly veterans who dropped off unit patches, Purple Hearts, photos of lost soldiers or old pairs of Army boots. But with many veterans now in their 60s, members of a younger generation — including grandchildren of veterans and the fallen — are making contributions.

On a recent day, a baseball card from a boy named Nicholas was propped against the wall, with a note that read "For my grandfather."

The practice wasn't foreseen by the memorial's planners, but the first offering came even before the monument was completed, a Purple Heart laid in the foundation by the brother of a dead soldier.

At the beginning, a memorial staffer collected the items on the belief that people would want them back.

When they continued to pile up, with little sign of abating, the Park Service decided in 1986 to treat the items as museum pieces.

"It was unheard of for people to come to a site over a protracted period of time and leave objects," said Duery Felton, the collection curator and a Vietnam veteran. "These objects became a collection. Before that, they were just things left at the memorial."

Jan Scruggs, a veteran who came up with the idea for the memorial and the president of the Vietnam Veterans Memorial Fund, said the wall changed the way people pay respects and grieve at memorials and at the sites of tragic events — such as the World Trade Center in New York and the bombed federal building in Oklahoma City.

"It is a beautiful thing," Scruggs said. "It shows that those who we know and who were a part of our lives and who aren't with us anymore still have an impact on us."

Park Service workers collect the mementos every few days and ship them to a temperature-controlled warehouse in an office park in suburban Landover, Md., about 20 miles away.

Each piece is cataloged. Some are kept in locked cabinets, others alongside long shelves of antique furniture from other historic sites. The warehouse holds more than 45 different collections, and the Park Service says there is no easy way to say how much it costs to store the mementos from the wall.

Even seemingly mundane items are kept, like a Washington Metro subway ticket with 15 cents on it, to avoid discarding something that might have a hidden meaning. Some show significant forethought, like a carefully made homemade replica carousel; others seem to be tokens left by people unexpectedly moved by the monument. Flowers and other perishables are not kept.

"We get messages on Popsicle sticks and bubble gum wrappers," said Pam West, director of the repository.

Much of the trend likely stemmed from the diverse backgrounds of U.S. troops, some of whom came from cultures where such items were a part of burial traditions, said Kristin Hass, a University of Michigan professor who wrote a 1998 book on the practice of leaving messages and mementos at the wall.

"They are speaking to the dead and to the place of the dead in culture," she said.

There are notes between buddies who served together, and messages of uncertain meaning like the unbroken, dry cigarette or the roll of toilet paper. Felton said both would be precious to a soldier spending days in the bush.

Others are stark testaments to the Vietnam experience. Felton pointed to one of the dozens of pairs of worn combat boots left at the memorial.

"These boots have character, they tell a story," he said. "I walked and walked, I fell down the side of the hill, the monsoon came in, I went through the rice paddies, I pulled leeches off of me, I jumped in the ditches, I jumped out of helicopters. They tell a story."

The collection includes items taken from the enemy — a dented canteen, an ammunition belt for an AK-47. There is a letter from an American soldier to the North Vietnamese soldier he killed that asks: "Why you didn't take my life I will not know."

Felton pulls out a whole drawer of Purple Hearts, another of military patches, and a shelf of uniform caps. There is a plaque made by a group of veterans in a post-traumatic stress therapy class, along with a series of barbed wire garlands to memorialize the eight women on the wall.

The Park Service does not try to research the origin of the items or explain why they were left. When they are exhibited, it is with scant written explanation, leaving viewers to draw their own conclusions.

But Felton wonders about some. He pulls out an open bottle of champagne with two glasses. Are they a statement about what could have been but was lost? Do they symbolize dreams and hopes derailed?

John Rowan, president of the Vietnam Veterans of America, says seeing the names is what motivates people to leave things behind, a way to commune with the dead. Rowan left the only poem he wrote at the memorial in the 1980s.

"It's a personal connection. It's a way to attempt to reach through the wall to a person whose name is there," he said.