Nested objects and parts

Staff sometimes need to describe a possession at several levels. A book contains pages and passages, supports annotations, may hold an inserted photograph. A camera includes components and modifications. A container holds separate deposited items. Staff record the relevant part or containment relation alongside the whole.

The level of detail follows the activity. A general catalog entry may describe the book as a whole. A correspondence reply requires the particular passage and annotation. A repair requires the affected component and its replacement. An inserted photograph can have separate authorship and custody even while remaining inside the book.

Staff preserve position, duration, permission, changes. Removing the photograph changes the containment relation. Rebinding the book may alter location references. Propagating a plant creates a related material instance. Action records and identifiers support these distinctions without requiring every unremarked part to become a separate enrollment.