An alternate made on 3 Mar 2013, in the 1870 US Census.
Alternate was made to the head of household, all but the last two members of the household were checked to include the alternate surname. Those who were not checked don't have the "black" alternate to nowhere.
I didn't add specific "reason" data, I apparently selected "incorrect in image" from the reason pull down menu, which is now being written in sentence form. Comparing this to the example above in the 1850 Census, I think the system "reason" selected disappears if you include some specific data.