Maybe you can already do this, if so please let me know how, but at the minute in SilverStripe you can set the Access options for a page to be accessibly to a specific group. However this setting doesn't pass down to Secondary, Tertiary etc pages below that page.
Scenario, I want to create a group for a set of people to be able to edit one page and it's subsequent siblings. However if they create a page without setting the Access options to just be their group, people in other groups can edit that page.
Good point. I think, rather than it always default to it's parent access settings, there could be a checkbox (checked by default) which marks this has having inheritable access settings. If it's not checked, then subsequent pages that are created as children of the page don't inherit its settings.
For now, you can always create your own custom code to do this. For example:
This code would set the "EditorsGroup" field in the SiteTree table to the parent page's EditorsGroup field, if the parent exists. This would obviously not do anything for the root level pages in the tree.
As willr said, please open a ticket on our open source tracker here: [url]http://open.silverstripe.com/newticket[/url]