This is this step I'm asking about (see attached image). I have found no discussion anywhere addressing the issue of whether it is admissible or advisable to register unpublished works from more than a single year. In my case I would like to register images taken 2010-2012. I would simply put 2012 as the year of completion.
Image was taken from this website. This page is helpful, but does not address the issue as far as I can see:http://asmp.org/tutorials/online-registration-eco.html#.UNH2YzNKDbw