Paragraph and character styles can be linked to a parent when they must remain in sync but for a few attributes which are forced in the child style.
E.g. all Heading x styles are descendants of Heading so that the heading font can be set in Heading different from Default Style which propagates down to Body Text. The net result is one font face for ordinary text and one font face for headings.
Similarly, there is a common frequent need for similar layout in pages. Margins must be the same to display a consistent layout but other element may differ: header title when not set by fields, header suppressed on first chapter page, …
Take for example the “classical” page styles for a chapter: First Page, Left Page, Right Page. They must all be set separately, the user caring to make them consistent. If, in the process of proof-reading the document, margins must be changed to enhance the layout, once again all three styles must be updated the same. The task would be easier and much more reliable if the styles could be linked to some other and the modification would propagate down to the child-styles.
Before I submit an enhancement (which has low chances of being implemented soon considering the number of pending bugs), does anybody know why page styles can’t be linked?
From a superficial point of view, I don’t see why this can’t be done. Since it involves “only” the style dictionary and its processing while laying out the document, I hope this is not due to a blocking limitation in ODF.