Diagnostic codes: may-not-export: A file in a `mayNotExport` rule has an export of the kind the rule refuses: a default export, an `export *` or `export * as`, or a named export whose name matches the rule's pattern. # may-not-export > A file in a `mayNotExport` rule has an export of the kind the rule refuses: a default export, an `export *` or `export * as`, or a named export whose name matches the rule's pattern. Rule violations. This text is what `archangel docs may-not-export` prints. A file in a `mayNotExport` rule has an export of the kind the rule refuses: a default export, an `export *` or `export * as`, or a named export whose name matches the rule’s pattern. ## Example ```ts // rule({ files: 'src/**', mayNotExport: 'default' }) export default function App() {} ``` ## What to do Export the value by name, or pass on the names one by one instead of `export *`. The violation is at the line of the export. A violation about a file is permitted only through the baseline, not an exception comment.