A glossary of terms used on this site

The CHS Technical Working Group has focused on issues of stable scholarly reference in a digital environment. We use the following terms in the technical senses given here:

canonical identifier

Either a CTS URN or a Collection identifier.

CTS URN

A reference in a URN syntax with explicit semantics for referring to passages of text objects. The text objects are identified in a FRBR-like hierarchy. Passages references are expressed in a hierarchy of traditional citation elements. Using subreferences, CTS URNs may point to elements of a specific version of a text as small as a single character.

CTS URN subreference

An optional component of CTS URN references referring to smaller sections of text than the smallest unit of the canonical citation hierarchy. CTS URN subreferences are expressed as indexed substrings within a canonically identified component, and are therefore only possible when a version or exemplar of a text object specific to some language is identified.

Collection ID

A canonical identifier for an object in a collection, composed of an ID value qualified by a data namespace. With the scope of the specified data namespace, the ID value is guaranteed to be unique. Collection IDs are currently used in to refer to objects in Collection Services, and in Image Processing Services, and are planned for use in GIS Services.

data namespace

XML namespaces use URIs to identify a definition of an object's structure such as a schema; data namespaces identify a set of objects that share a common definition expressible as an XML namespace. Within a given data namespace, each object is guaranteed to have a unique identifier. The combination of a uniquer identifier with the data namespace is a Collection ID.

edition

The third, version-level component of a CTS URN is explicitly identified in a CTS TextInventory as either an edition in the original language of the work, or as a translation into a specified language. The version corresponds to the FRBR expression.

exemplar

In CTS URNs, the fourth component of the text object hierarchy, identifying a specific physical instance of the text. The exemplar corresponds to the FRBR item.

image subreference

An optional extension to a Collection ID to refer to a subsection of an Image object. The subreference is expressed as a series of four coordinates identifying a rectangular section of an image in (scale-independent) percentage values.

language triplet

A proposed overloading of standard codes used in the xml:lang attribute that can be placed on any XML document. The purposed of the proposed conventions is to capture the language of the original document, the writing system of the original document, how that writing system is mapped onto a digital character set, and what digital character encoding is using in the resulting digital document. (See this discussion of language triplets.)

registry value

A standard identifier for an object, as recorded in a Registry Service, independent of any specific representation, or appearance in any Collection. (Note, however, that the Registry Services protocol does guarantee that each entry must be attested by at least one canonically identified example.) Registry values may be organized to provide unique identifiers composed of hierarchically structured components, such as the textgroups, works, versions and exemplars of a CTS URN.

textgroup

The topmost component in a CTS URN's identification of a text object. Note that this component has no parallel in the FRBR object hierarchy.

translation

The third, version-level component of a CTS URN is explicitly identified in a CTS TextInventory as either an edition in the original language of the work, or as a translation into a specified language. The version corresponds to the FRBR expression.

version

In CTS URNs, the third component of the text object hierarchy, explicitly identified in a CTS TextInventory as either an edition in the original language of the work, or as a translation into a specified language. The version corresponds to the FRBR expression.

work

In CTS URNs, the second component of the text object hierarchy, a notional text corresponding to the FRBR work.