In Facebook’s web architecture, "rdr" stands for . When you see this parameter, it indicates that the site has automatically moved you from one URL to another to match your device type (mobile vs. desktop) or your current login status.
: Tap on "Log Out."
: Tap on "Settings."
If the button is unresponsive, the manual URL method is a viable backup. To make the link you provided work, you would simply need to add the missing colons so it reads: https://m.facebook.com/home.php?rdr (though typically, simply clearing your browser cache and cookies is the safest way to force a logout if the buttons are broken). https //m.facebook.com/home.php rdr log out