A global area or stack will be exactly the same everywhere it is used. Edit it in one place, and the change will show everywhere.

Page type defaults are the same when pages are created, but when you edit an individual page, the contents will diverge from the defaults and the contents of other pages.

When you subsequently edit the defaults, there is an option to propagate changes to all child pages (with consequences).

Unfortunately there is no 'stack with parameters' that would enable something in-between the two.

Hi Thanks for your reply.

I think I get what is going on now. However I do not know if it is a bug or not but even when to select to proegate the change onto child pages and then you go to the page and the popup box says this is an alias of page defaults, the change does not happen.

The only way to keep this is do not modify the page default page again otherwise you need to recreate the pages again.

As far as I know it is intended behaviour. When there is any divergence, it becomes a logical nightmare to resolve propagated changes, hence the current behaviour is the safest option.