Represent relationships of composition using a Parent column – To specify composition relationships (such as columns in a
table, classes in a package, or attributes in a class) between objects on
different worksheets, specify the parent or location for the sub-object in a
Parent column. You can specify a multi-level hierarchy
of parents separated by a qualified name separator.
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Note: Whereas specifying a collection of sub-objects
in a single cell on the parent worksheet allows you to quickly populate
the collection, specifying sub-objects on a separate worksheet allows
you to detail all their properties.