Xic has a built-in design rule checking engine, based on rules provided in the technology file or interactively in Xic. Both interactive (performed after every geometry modification) and batch-mode checking (foreground or background) is supported, in all or a portion of the layout.
Errors are reported in a log file, and indicators added on-screen. Clicking on the indicator can provide a close-up view of the error and explanatory text.
There is a rule editor that gives the user complete control over the rules and parameters in use. Although a fairly complete set of built-in tests is provided, user-defined tests allow more specialized tests to be performed. Special layers and flags allow objects and regions to be ignored during testing.