StyleBoxAutoDelete is an option for cells that determines if a StyleBox wrapped around an expression should be automatically removed when the expression is edited.
This option is useful for creating templates that require user input. For example, suppose you want to create a template for calculating integrals. You can highlight the part of the expression that the user needs to edit by displaying it in a different style, such as using a red color for the font: . If you set StyleBoxAutoDelete True, the red color will disappear as soon as the user edits the expression.