Copying a link from a specific StackOverflow answer doesn’t seem to onebox.
##Link from answer
###Example link from answer
http://stackoverflow.com/a/30810322/406712
##Link from browser address bar
The link from the browsers address bar just link to the Question and don’t link to the answer - if you were to click the normal link yourself it goes to a different location to the onebox.
http://stackoverflow.com/questions/400212/how-do-i-copy-to-the-clipboard-in-javascript/30810322#30810322
####Onebox
####Normal Link
http://stackoverflow.com/questions/400212/how-do-i-copy-to-the-clipboard-in-javascript/30810322#30810322