On the Whitman Archive encoding project, the words "work" and a "document" have specialized meanings. A "document" is a particular textual object, for example, an instance of a particular poem, like the "Song of Myself" in the 1855 Leaves of Grass or the first draft of "The Sleepers." A "work" is an intellectual abstraction, the idea of a literary text rather than a particular instance of it. A work is what we are usually referring to when we speak of "Song of Myself" or Leaves of Grass. This distinction is important to our system of "relations" tagging, which connects individual drafts, editions, etc. to the poems, books, etc. that they are versions of.