METS: Metadata Encoding and Transmission Standard. METS is intended to provide a standardized XML format for transmission of complex digital library objects between systems. As such, it can be seen as filling a role similar to that defined for the Submission Information Package (SIP) and Dissemination Information Package (DIP) in the Reference Model for an Open Archival Information System. dmdSec: Description Metadata Section. This section records all of the descriptive metadata for all subobjects in the METS object. Metadata can be either included in the METS hub document (mdWrap) or referenced via an identifier/locator (mdRef), a la Warwick Framework. Multiple mdRef and mdWrap elements are allowed so that descriptive metadata can be recorded for each separate subobject within the METS object. amdSec: Administrative Metadata Section. This section records all of the administrative metadata for all subobjects in the METS object, and is divided into four subsections: techMD (technical metadata), rightsMD (intellectual property rights metadata), sourceMD (provenance metadata) and preservation (preservation metadata). Each of these subsections follows the mdSecType model, so that they can either include metadata within the METS hub document (mdWrap) or reference it via an identifier/locator (mdRef). Multiple mdRef and mdWrap elements are allowed so that administrative metadata can be recorded for each separate subobject within the METS object. fileGrp: File Group. File Groups record information regarding all of the data files comprising the digital object, including both master files and derivatives. File Groups may both repeat and nest to provide an organizing framework for data files. structMap: Structural Map. The structural map is the heart of a METS document, defining the hierarchical arrangement of a primary source document which has been digitized. This hierarchy is encoded as a tree of 'div' elements. Any given 'div' can point to another METS document via the 'mptr' element, or to a single file, to a group of files, or to segments of individual files or groups of files through the 'fptr' and subsidiary elements. div: Division of a structural map. Nested div elements define the hierarchical structure of the digital library object. Div elements are linked to the content corresponding to that div by subsidiary mptr and fptr elements. Div elements have the following attributes: 1. ID (an XML ID); 2. N: an integer representation of this div's order among its siblings (e.g., its page number); 3. NUMBER: a string representation of this div's order among its siblings (e.g., "Page xii"); 4. LABEL: a string to describe this div to an end user viewing the document, as per a table of contents entry; and 5. DMD: a set of IDREFs to descriptive metadata sections within this METS document applicable to this div. mets Complex Type. A METS document consists of four possible subsidiary sections: dmdSec (descriptive metadata section), amdSec (administrative metadata section), fileGrp (file inventory group), and structMap (structural map). It also has four possible attributes: ID (an XML ID), OBJID (a primary identifier assigned to the original source document), LABEL (a title/text string identifying the document for users), and TYPE (a type for the object, e.g., book, journal, stereograph, etc.). amdSecType: Complex Type for Administrative Metadata. The administrative metadata section consists of four possible subsidiary sections: techMD (technical metadata for text/image/audio/video files), rightsMD (intellectual property rights metadata), sourceMD (source metadata i.e. provenance), and preservationMD (preservation metadata necessary to maintain the digital library object in the long term). amdSecType has a single attribute, ID (XML ID). techMD: technical metadata. The techMD element provides a wrapper around a generic metadata section, which should contain technical metadata regarding a file or files. It has a single attribute, ID, which file/fileGrp elements can use to reference the technical metadata that applies to them. rightsMD: intellectual property rights metadata. The rightsMD element provides a wrapper around a generic metadata section, which should contain IP rights metadata. It has a single attribute, ID, which file/fileGrp/div elements can use to reference IP Rights metadata that applies to them. sourceMD: source metadata. The sourceMD element provides a wrapper around a generic metadata section which should contain source/provenance information. It has a single attribute, ID, which file/fileGrp elements can use to reference the source metadata which applies to them. preservationMD: preservation metadata. The preservationMD element provides a wrapper around a generic metadata section which should contain preservation metadata. It has a single attribute, ID, which file/fileGrp elements can use to reference the preservation metadata which applies to them. fileGrpType: Complex Type for File Groups. The file group is used to cluster all of the digital files composing a digital library object in a hierarchical arrangement (fileGrp is recursively defined to enable the creation of the hierarchy). Any file group may contain zero or more file elements. File elements in turn can contain a FLocat element (a pointer to a file containing content for this object) and/or a FContent element (the contents of the file Base64 encoded). file: File element. The file element provides access to content files for a METS document. It has the following attributes: 1. ID: an XML ID for the element; 2. MIMETYPE: the MIME type for the file; 3. SEQ: an integer indicating the sequence of this file relative to the others in its file group; 4. SIZE: the size of the file in bytes; 5. CREATED: the date of creation for the file; 6. OWNERID: a primary identifier assigned to the file by its owner; 7. ADMID: IDREFS to administrative metadata sections in the METS document that correspond with this file; and 8. GROUPID: an identifier that establishes a correspondence between this file and files in other file groups. Typically, this will be used to associate a master file in one file group with derivative files in other file groups. A file element may contain an FLocat element, which provides a pointer to a content file, and/or an FContent element, which wraps an encoded version of the file. FLocat: File Location. The FLocat element provides a pointer to the location of a content file. It has two attributes: ID (an XML ID), and LOCTYPE (the type of locator contained in the FLocat element). FContent: file content. The FContent element is used to deliver a content file for a METS document within the METS file itself. The content file must be Base 64 encoded, and contained within the FContent wrapper element. structMap Complex Type div: Division. The METS standard represents a document structurally as a series of nested div elements, that is, as a hierarchy (e.g., a book, which is composed of chapters, which is composed of subchapters, which is composed of pages). Every div node in the structural map hierarchy may be connected (via subsidiary mptr or fptr elements) to content files which represent that div's portion of the whole document. The div element has the following attributes: 1. ID (an XML ID); 2. N: an integer representation of this div's order among its siblings (e.g., its page number); 3. NUMBER: a string representation of this div's order among its siblings (e.g., "Page xii"); 4. LABEL: a string to describe this div to an end user viewing the document, as per a table of contents entry; and 5. DMD: a set of IDREFs to descriptive metadata sections within this METS document applicable to this div. Div Complex Type mptr: METS Pointer. The mptr element allows a div to be associated with a separate METS document containing the content corresponding with that div, rather than pointing to an internal file or file group. A typical instance of this would be the case of a METS document for a journal run, with a div elements for each individual journal issue. The div elements for the issues might point to separate METS documents for each issue, rather than having files and file groups for every issue encoded in one document. The mptr is derived from the XLink recommendation of the W3C, and should be used according to W3C guidelines. fptr: File Pointer. The fptr element associates a div element with content files that represent that div. It can either point to a file directly itself, via the FILEID attribute, or it can do more complex links to content via the subsidiary par and seq elements. par: Parallel files. The par element should used to link a div to a set of content files when those files should be played back in unison to display the content to the user. Individual area subelements within the par element provide the links to the files or portions thereof. seq: Sequence of files. The seq element should be used to link a div to one or more content files when those files should be played sequentially to display content to a user, or where there is only one file to link, but the link from div to file requires identifying a subcomponent of a file. areaType: Complex Type for Area linking. The area element provides for more sophisticated linking between a div element and content files representing that div, be they text, image, audio, or video files. An area element can link a div to a point within a file, to a one-dimension segment of a file (e.g., text screen, image line, audio/video clip), or a two-dimensional section of a file (e.g, subsection of an image, or a subsection of the video display of a video file. The area element has no content, and the following attributes: 1. ID: an XML ID; 2. FILE: an IDREF to the file element being pointed to by the div; 3. SHAPE: a text string defining the shape of a two-dimensional area being referenced in a link file; 4. COORDS: a text string representing a set of visual coordinates within an image (still image or video frame). The COORDS and SHAPE attributes should be used as in HTML 4; 5. BEGIN: a beginning location in a referenced file; 6. END: an ending location in a referenced file; 7. BETYPE: the syntax used in specifying the BEGIN and END attributes (byte offset, IDREF value, or SMPTE time code); 8. EXTENT: the duraction of the segment; and 9. EXTTYPE: the syntax used in specifying the extent (byte length or SMPTE time value). mdSec (metadata section) Complex Type mdRef: metadata reference. The mdRef element is a generic element used throughout the METS schema to provide a pointer to metadata which resides outside the METS document. It has the following attributes: 1. ID: an XML ID; 2. LOCTYPE: the type of locator contained in the body of the element; 3. MIMETYPE: the MIME type for the metadata being pointed at; 4. MDType: the type of metadata being pointed at (e.g., MARC, EAD, etc.); 5. LABEL: a label to display to the viewer of the METS document identifying the metadata; and 6. XPTR: an xptr to a location within the file pointed to by the mdRef element, if applicable. mdWrap: metadata wrapper. The mdWrap element is a generic element used throughout the METS schema to allow the encoder to place arbitrary metadata conforming to other standards/schema within a METS document. The included metadata can either be encoded in XML, in which case it may be placed directly within the mdWrap element, or it can be Base64 encoded, and placed within a subsidiary binData element. A wrapper to contain Base64 encoded metadata.