I don't understand the caching options in the Macro Properties.

If anyone has the time to explain the following i'd be very grateful!

* Cache Period (Seconds)
- Does 0 imply caching is disabled, or does it mean as long as IIS doesn't recycle, or something else?

* Cache By Page (Default Yes)
- Does this mean that it's cached for all users by url? Or does it mean that it's cached for all users by umbraco page? Does page cacheing imply that the macro isn't run but the result is returned until the cache is refreshed?

* Cache Personalized (Default False)
- Does this mean that the item is cached per user but not neccesarily by page, thus that the result of a certain macro is given to the user next time he hits any page (cache by page off) regardess the macro logic?
- In combination with Cache By Page it uses both the current user and page to identify the cached item.

** If I have a member login control on a page and I want to ensure it's not cached in any way at all, what is the correct cache setting? Is the default setting enough? (Cache Period : 0, Cache By Page: True, Cache Personalized: False)

Thanks! :)