About Placing Annotations on a Reference Plane
You can place standalone annotations and Annotation Elements on a reference plane while creating them or move existing annotations to a reference plane.
Note the following points about annotations on a reference plane:
If you place an annotation on its reference plane and unfreeze the annotation plane reference, then such an annotation will automatically follow the position changes of the reference plane. However, if you freeze the annotation plane reference of an annotation, then the annotation maintains its position even if the reference plane moves.
You can place a Driving Dimension Annotation Element (DDAE) on a reference plane. However, the DDAE does not follow the position changes of the reference plane as their annotation plane reference is frozen.
Z-Extension lines are created for all the annotation types except Set Datum Tag Annotations.