Normally when I click on a link in Chrome with a middle mouse button, the page open s in a new tab. I find it useful and would like it to always work that way.

But on some sites, specifically SharePoint sites I'm often working with, middle click on certain links opens the page in the same tab. Example can be found on this publicly available SharePoint demo page when clicking on "Internet Sites" or "SharePoint resources" links with middle mouse button.

Those menu items seem like a link (they definitely have URL assigned). Why do them open in the same tab instead of a new one, when middle clicked? Can this behavior be changed in Chrome's settings or using some addon?