I wonder to get the point when there are different (about results). I created three files to represents each both situations (a include directive page, a jsp:include directive page and a page to be imported).
Content to be imported
Both pages behavior are the same, but I was thinking that in a include directive situation the content will just be displayed once, and if try to refresh the browser the Date displayed are the same from the old refreshing, but I noticed that the content is updated each refresh. I really don´t know when the pages behavior will be different.