Documents contain two types of properties; those that are calculated and those that you can manually edit. Modules, sections, topics, web pages, and packages have editable properties that you can set and change at any time. The properties you set are saved with the document and travel with it on operations such as export and import.
Initial Values
Some editable document properties start with an initial value. The initial value assigned depends on how the document was created. New documents that are created by linking them to an outline inherit the same value as the parent. New documents created in the Library as stand-alone documents not linked to a parent, adopt the system setting in the Options dialog box as the initial value. As with any editable property, you can change document's initial value at any time.