That's the child album entry you linked to (a child album is a reprint or alternate printing). Generally you should edit the parent entry since child entries get some of their information from the parent. (Unless your information is specific to the reprint)
Here's the parent album:
http://vgmdb.net/album/4
Choose "Edit" on the top right and select "Edit Album Info". The Notes section is all the way at the bottom, under Supplementary Information.