Renaming Articles
if someone had linked to this page from another site the link would be broken.
Create an article named: "test article"
Click on edit, changed the title to: "test article changed"
If I click the link from the list of articles in that namespace, I get the new page with the changed title and the title is also changed in the listing, but if I enter the link to the old article that was called "test article" I get a page that says "There is currently no text in this page." and nothing happens, I'm not redirected to the new page with the name "test article changed" so if someone had linked to this page from another site the link would be broken.
In mediawiki, if you change a page title then you can still type in the old url and you will get the new page so the link doesn't break. If you have mediawiki installed you can try to create a page and save it and copy the link, then change the title of the page. Now paste in the old link and you will still get to the page.