# Hover Expression

You may display additional information about a note when the cursor hovers over the note. The hover expression is only displayed in Maps and Outlines.

The attribute `$HoverExpression` lets you specify the information that will be shown while hovering. A note may have its own hover expression, but often will inherit hover expression from a prototype.

To add or change the hover expression, open the Text inspector, and switch to the Hover pane

The `$HoverExpression` attribute is simply an expression in action code, just as used in Tinderbox rules, container actions, and agent actions. If `$HoverExpression` is empty, no hover expression is displayed.

For example:

HoverExpression | typical display
--- | ---
`$WordCount+" words"` " | 7500 words
`$WordCount+" words\n\n+$Text"` | 7500 words Now is the winter of our discontent…

For more information on actions and expressions, see Actions, Expressions, and Rules.