http://openannotation.org/spec/core/ Abstract
The Open Annotation Core Data Model specifies an interoperable framework for creating associations between related resources, annotations, using a methodology that conforms to the Architecture of the World Wide Web. Open Annotations can easily be shared between platforms, with sufficient richness of expression to satisfy complex requirements while remaining simple enough to also allow for the most common use cases, such as attaching a piece of text to a single web resource.
An Annotation is considered to be a set of connected resources, typically including a body and target, where the body is somehow about the target. The full model supports additional functionality, enabling semantic annotations, embedding content, selecting segments of resources, choosing the appropriate representation of a resource and providing styling hints for consuming clients.
Namespaces
The Open Annotation model defines a namespace for its classes and properties, and uses several others as listed below. The namespace URI will always remain the same, even if the ontology changes. All versions of the ontology will remain available from version-specific URLs, and the namespace URI will provide access to the most recent version.
The following namespaces are used in this specification: