His birth certificate read only “(baby boy) Pauson.” Name to come.

His father had disappeared. His mother — in his words, “a pack rat who takes a really long time to decide on anything” — did not pick a first name at the hospital in San Francisco in 1990. And she never followed up, leaving him in a rare and strange limbo…

“Sometimes I thought it was kind of cool, like the Man With No Name in ‘The Good, the Bad and the Ugly,’ ” he said last week in his subsidized apartment here, which is provided by a group that helps former foster-care children. “But can you imagine how hard it was to fly without an official ID?”