Assembly Considerations

Datum targets only appear in the root document of the current design window. If they appeared in the component itself, they would be shown in every occurrence of the component in an assembly. Having them in the root document of the design window provides flexibility and prevents multiple, unnecessary duplicates.

For example, in a table with four legs, each leg is the same component, but each leg in the table assembly may need a different datum target, or no target at all. See the image below.