An archivist is an information professional who assesses, collects, organizes, preserves, maintains control over, and provides access to records and archives determined to have long-term value. The records maintained by an archivist can consist of a variety of forms, including letters, diaries, logs, other personal documents, government documents, sound and/or picture recordings, digital files, or other physical objects. An archivist is an information professional who assesses, collects, organizes, preserves, maintains control over, and provides access to records and archives determined to have long-term value. The records maintained by an archivist can consist of a variety of forms, including letters, diaries, logs, other personal documents, government documents, sound and/or picture recordings, digital files, or other physical objects. As Richard Pearce-Moses wrote: Determining what records have enduring value can be challenging. Archivists must also select records valuable enough to justify the costs of storage and preservation, plus the labor-intensive expenses of arrangement, description, and reference service. The theory and scholarly work underpinning archives practices is called archival science. The most common related occupations are librarians, museum curators, and records managers. The archivist occupation is distinct from that of librarian. The two occupations have separate courses of training, adhere to separate and distinct principles, and are represented by separate professional organizations. In general, the librarian tends to deal with published media (where the metadata, such as author, title, and date of publication, may be readily apparent and can be presented in standardized form), whereas the archivist deals with unpublished media (which has different challenges such as the metadata not always being immediately apparent, containing complications and variety, and more likely to depend on provenance). In addition, because archival records are frequently unique, some archivists may be as much concerned with the preservation and custody of the information carrier (i.e. the physical document) as with its informational content. In this regard, some would argue the archivist may have more in common with the museum curator than with the librarian. The occupation of archivist is also frequently distinguished from that of records manager, although in this case the distinction is less absolute: the archivist is predominantly concerned with records deemed worthy of permanent preservation, whereas the records manager is more concerned with records of current administrative importance. Because of this, the position duties for each occupation can easily intertwine, particularly if both occupations are present at an institution. Archivists' duties include acquiring and appraising new collections, arranging and describing records, providing reference service, and preserving materials. In arranging records, archivists apply two important principles: provenance and original order. Provenance refers to the creation of records and keeping different records separate in order to maintain context. Many entities create records, including governments, businesses, universities, and individuals. Original order is applied by keeping records in their order as established and maintained by the creator(s). Both provenance and original order are closely related to the concept of respect des fonds, which states that records from one corporate body should not be mixed with records from another. There are two aspects to arrangement: intellectual and physical. Both aspects follow the principle of original order. Archivists process the records physically by placing them in acid-free folders and boxes to ensure their long-term survival. They also process the records intellectually, by determining what the records consist of, how they are organized, and what, if any, finding aids need to be created. Finding aids can be box lists or descriptive inventories, or indexes. Even if the original arrangement is unclear or unhelpful in terms of accessing the collection, it is rarely rearranged to something that makes more sense. This is because preserving the original order shows how the creator of the records functioned, why the records were created, and how they went about arranging them. Moreover, the provenance and authenticity of the records may be lost. However, original order is not always the best way to maintain some collections and archivists must use their own experience and current best practices to determine the correct way to preserve collections of mixed media or those lacking a clear original arrangement. Archivists' work encompasses a range of ethical decisions that may be thought of as falling into three broad and intertwined areas: legal requirements; professional standards; and accountability to society in selecting and preserving documentary materials that serve as a primary source of knowledge, and influence collective memory and identity. In negotiating the ethical conflicts that arise in their work, archivists are guided by codes of ethics. The Society of American Archivists first adopted a code of ethics in 1980; the International Council on Archives adopted one in 1996.