Displaying a placeholder for null values

When a value is null, I don't want it to display as a 开发者_如何学Cblank. Instead, I want there to be some kind of default value like "N/A". How can I accomplish that?

You can use a formula field to detect the null value.

If IsNull({Product.Description}) then
"Not available"
else
{Product.Description}

Cheers