About Deleting Features
Deleting a feature removes the feature from the part permanently.
When you select a feature that has children for deletion, you must account for the children. You can delete them, but you can also save the children by editing their references.
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Normally, all the features are regenerated starting from the first modified feature or the first feature with an external reference, onward, when you select Regenerate. In calculating where to begin regeneration during Delete operations, features with an external reference are not considered.