Action code can also be the value of certain attributes. For example, I can prepend the created date of a note to its displayed name while keeping its actual name hidden and intact. I do this by entering action code into the $DisplayExpression attribute. When $DisplayExpression is empty, Tinderbox displays the note’s $Name. But when $DisplayExpression has a non-nil value, this gets evaluated and becomes the note’s new $DisplayName, which is the name you see in all the views. In other words, $DisplayName is $Name unless $DisplayExpression is set.