While browsing the web, you sometimes click a link that will open a new tab/window. Or, you might click the address bar to have it open a new browser window. There's nothing you can do to prevent this. However, with the _blank extension, you can get a heads up when clicking a link that will open a new tab/window. This will help you to decide whether or not you want to click that link. You can also have the extension automatically open links that will open a new tab/window, so you'll know in advance whether or not you should click it.

The _blank extension is only compatible with websites that use the target attribute to tell the browser to open links in a new tab/window.