Rated 5 out of 5 stars

As I said, simple and excellent :  right-click the tab in question and choose "Private Tab"… end of story. To cancel, right-click again and choose "Public Tab" ( or, if you're done, simply close the tab outright ). Allows you to have both public and private tabs within the same Firefox window. Didn't realize how much of a shortcoming the other (standard) way was until I saw this extension out of the corner of my eye . . . while searching for something else, no less. Serendipity, y'all. ;^˃

This review is for a previous version of the add-on (0.1.8.1).