Annotation Plane
ASME Y14.41 : Digital Product Definition Data Practices
A conceptual plane containing annotation that either perpendicularly intersects, or is coincident with one or more surfaces of a feature.
See Also:
Annotation, Surface, Feature
Alternate Definitions:

PTC - A datum plane that defines the orientation of the annotation item with respect to the 3D model. The annotation item is not actually placed on the Annotation plane, but on an imaginary plane parallel to the Annotation plane, and facing in the direction of the front of the Annotation plane. The actual location of this imaginary plane with respect to the model is determined by the first selected attachment for the annotation.