“We were going to some groups, sitting with them, asking for their names,” he added.

Conservationists at the museum are preparing to study the fabric and are researching how best to preserve it. The chief conservator, Jane E. Klinger, said her team was looking to construct containers to hold the documents — perhaps with plexiglass that protects from ultraviolet rays — which have so far been buried within a notebook Mr. Omari bought at the civilian prison to which he was moved in late 2012.

“That’s a very good solution for a lay person because they’re protected, flat, there’s an amount of cushioning,” she said, using white gloves and small metal tools to look through Mr. Omari’s notebook.

On Tuesday at the museum’s David and Fela Shapell Family Collections, Conservation and Research Center, about an hour’s drive from Washington, Mr. Omari unveiled the names of the prisoners to a small group of conservationists.

Flipping through the notebook’s worn pages, he revealed memories, all dated carefully on the top of every page.

Scribbled neatly on the book’s tattered front are the words “la dolce vita,” or “the good life.”

“I don’t take it out so much,” he said in slow, hushed English. “It’s so emotional for me when I see it.”

“I was writing it for myself, trying to see that life is beautiful even after all that happened,” he added.