Model-Based Definition > Model-Based Definition > Annotation Features > Creating Annotation Features > Placement Behavior of Set Datum Tag Annotations
  
Placement Behavior of Set Datum Tag Annotations
The following points describe the behavior of the set datum tag annotations when you place them on a datum plane or datum axis using the placement options in the Set Datum Tag dialog box.
• If you place an annotation using On Datum, then the set datum tag annotation appears attached to the datum. If you create a set datum tag annotation for a datum plane, then the location of the set datum tag annotation on the plane is fixed. However, you can specify its viewing direction and Right direction using its Annotation plane. If you create a set datum tag Annotation for a datum axis, then you can redefine the location of the set datum tag annotation along the axis using Pick on Datum. The Annotation plane should be parallel to the axis that the set datum tag references.
• If you place an annotation using In Dim, then the set datum tag annotation is placed on the selected dimension. If the dimension is a driving dimension, then the set datum tag annotation is visible only when that dimension is displayed. If the dimension is a driven dimension, then the set datum tag uses the annotation plane of the driven dimension.
• If you place an annotation using In Gtol, then the set datum tag uses the annotation plane of the GTOL to which the set datum tag annotation is attached.
• If you place an annotation using On Geometry, then you can place a set datum tag annotation created for a datum plane only on a coplanar surface and a set datum tag annotation created for an axis only on a cylindrical surface that is coaxial with the datum axis referenced by set datum tag.
The solid triangle attached to a set datum tag annotation that is placed on a surface is normal to the surface regardless of the direction of text.
You can also place a set datum tag annotation created for an axis on a circular edge or curve if the selected annotation plane contains the selected reference. The set datum tag annotation is normal to the selected edge or curve and the solid triangle appears attached to the edge or curve.