Update Issue board documentation

doc/user/project/issue_board.md

@@ -31,10 +31,9 @@ Below is a table of the definitions used for GitLab's Issue Board.
 There are three types of lists, the ones you create based on your labels, and
 two default:
 
-- **Backlog** (default): shows all issues that do not fall in one of the other
-  lists. Always appears on the very left.
-- **Done** (default): shows all closed issues. Always appears on the very right.
-- Label list: a list based on a label. It shows all issues with that label.
+- **Backlog** (default): shows all opened issues that do not fall in one of the other lists. Always appears on the very left.
+- **Done** (default): shows all closed issues that do not fall in one of the other lists. Always appears on the very right.
+- Label list: a list based on a label. It shows all opened or closed issues with that label.
 
 ![GitLab Issue Board](img/issue_board.png)