MIL-STD-31000B : DOD Standard Practice Techincal Data Packages
An annotation orientation refers to the plane or the parallel plane in which the annotation lies, the viewing direction and the right direction or text rotation. One should maintain text orientation in a view that provides consistency for viewing. The orientation of the annotation plane should be maintained relative to the model geometry as the model is manipulated in 3D to comply with ASME Y14.41 section 5.2.3.
See Also:
Annotation, Geometry