An assembly-based feature which affects only the parts you select.

For profile-based features, the reference plane, profile, extent definition, and surface geometry resides in and can only be viewed from the assembly document where the feature was constructed.

This option is useful when you want to modify one or more commonly-used parts, but do not want to affect other instances of the same parts in the active assembly or other assemblies that reference those parts.

You do not need write access to the affected part files to construct an assembly feature.