What rules apply when IE9 decides how to open popups?

Question

I found that when the default popup option: let internet explorer decide how pop-ups should open is checked, IE9 opens some popups in new tab and others in a new Window... Sounds coherent to the option... But the question is, how does IE decide?

I have two links:

<a href="http://www.google.com" target="_blank">Link to google</a>

<a href="/somewhereOnMySite/test.html" target="_blank">Link to some other page</a>

The first one (Google) will open in a new Window, whereas the second one opens on a new tab...

I thought I should look for these rules, it just seems that pages on the same site get a tab and external links get a new window... Is there any documentation that can confirm this or have some more elaborate description?

Regards

Answer 1

Three Microsoft articles may apply here :

Your Tab Settings

Basically what this will do is open any pop-up without size or other restrictions in a new tab, the rest will open in a new window. For users experienced with tabbed browsing this is typically the best option, as it allows most windows to open in tabs, but allows pop-up style windows to open in a new window.

Tabbed browsing in Internet Explorer 8: frequently asked questions

If you opt to let Internet Explorer decide how to display pop-ups, it will display the pop-up in a new window if the pop-up specifies size or display requirements. Otherwise, the pop-up is displayed in a new tab.

Open OWA messages in a new tab instead of a pop-up window

The reason that it opens in a new window instead of a new tab is because the pop-up link holds window size information and disables certain browser interface elements such as menus, back/forward buttons, etc… While this does give it a more “application” look and feel, it indeed makes it harder to group all your OWA activity together.

The answer is probably that the Google page has some restrictions on its display that cause IE9 to consider it as an "application" and to open it in a new window. As the Google page contains lots of CSS and JavaScript, one can understand IE9 making that error, especially since IE9 does not support the latest CSS standards.

Google, on the other hand, dropped support for IE9 on 2013, so does not make today any effort to make its pages understandable by IE9. Officially, Google now only supports IE11.