I just noticed yet another time that selecting text from a post contains invisible characters - in this particular case I selected the URL from this post: by selecting from the starting h of http and moved the mouse a bit to the right and down so it selected the entire rest of the line.   When I then clicked "go to" in my context menu (using Chrome) I got a 404 which confused me because the url is valid. I eventually found out that the selected text contained some UTF-8 BOM bytes at the end. Also when inspecting the elements it showed this:     which according to a google search is a zero width no-break space - turning off JS makes them disappear. The weird spans are also shown with Firefox however selecting the text does not cause it to contain garbage.   Edit: I found what is causing the spans with the ZWNBSP - its the "quote selection" popup that leaves them there. So the issue I am describing here only happens when you selected the text, deselected and then selected again to contain the hidden ZWNBSP character.