About Reference Types
Annotation Element references include all the geometric references of its annotation item. For example, if an Annotation Element includes a note, and the note is attached to two edges, then these edges and the note's Annotation plane are automatically included in the References list of the Annotation Element.
Optionally, you can explicitly select additional Annotation Element references of the following types:
Datum points and geometry vertices
Datum curves, geometry edges, and surface edges
Solid or quilt surfaces
Datum axes
Coordinate systems
Datum planes
Intent objects
Components (only available for Annotation features within an assembly)
Sub-assemblies (only available for Annotation features within an assembly)
Entities on layers (combinations of any of the entity types above, but not rules)
Entities through selection, for entities such as chains of edges or sets of surfaces.
Designated area, that is, a region that you can create on multiple surfaces.
Edges and vertices of planar, offset, and zonal cross sections.
These references can be Weak or Strong. A loss of Strong reference causes the failure of the Annotation feature. A loss of a Weak reference does not cause the failure of the Annotation feature, but it may make the annotation inactive.
By default, all the additional Annotation Element references that you select are Weak. You can change a reference to Strong by selecting the checkbox in the Strong column next to the reference name in the appropriate reference collector in the ANNOTATION FEATURE dialog box.
You can remove a previously selected reference by right-clicking its name in the collector and selecting Remove on the shortcut menu.
You cannot remove the automatically populated references directly from the References collector. To change these references, redefine the properties of the annotation item. You can, however, change the status of these references (Strong or Weak) by selecting or clearing the checkbox next to the reference name in the References collector.