It is widely recognized that the proliferation of annotation schemes runs
counter to the need to re-use language resources, and that standards for
linguistic annotation are becoming increasingly mandatory. To answer this need,
we have developed a framework comprised of an abstract model for a variety of
different annotation types (e.g., morpho-syntactic tagging, syntactic
annotation, co-reference annotation, etc.), which can be instantiated in
different ways depending on the annotator's approach and goals.