"Nesting" refers to the use of tags within tags - for example, statements within statements, or statements within statements. There are valid reasons to nest your code, but avoid nesting too deeply. Nesting impacts application performance - but worse, it also tends to make your code less manageable. Well written (and well planned) code will seldom need deep nesting. If you find yourself nesting more than a few levels deep, take a step back, and rethink your code. (Applies to: ColdFusion All)