Extensions to CITE Collections

The CITE URN defines a syntax and semantics for referring to discrete objects; CITE Collection Services allow you to retrieve structured textual representations of objects using CITE URNs. Extensions to CITE Collections support extending the four required components of a CITE URN with an optional, extension-specific component, and can provide methods for identification and retrieval that take advantage of that extended notation.

Our work to date has defined one extension to CITE Collections: the CHS Image extension.

CHS Image Extension

Extended URN notation

The CHS Image Extension extends CITE URNs so that you can cite a particular region of an image. See an overview of citing images with regions of interest.


It defines a series of methods for working with image data, including a method for retrieving binary image data by URN citation. See a summary of requests in the CHS Image Service.