|Dotfuscator > Configuring Dotfuscator via the GUI > The Rules Editing Interface > Creating Custom Rules|
You can create custom rules by adding nodes to the rule editing view. Depending on the type of rule, you can attach regular expressions and/or other selection criteria to the rule. Once the rule is configured, you can preview its effects by right clicking on the node and selecting Preview from the menu. Items selected by the rule will be shaded in the application tree view. Each type of rule is covered in the following sections.