The best way for documenting private methods is to use 

```js
/**
 * (...)
 * @private
 */
```

That way IDEs like WebStorm can use the type information provided by jsdoc (thanks to `/**`), but the documentation is discarded by strong-docs (thanks to `@private`).

Comments starting with `/*!` are usually used for license boilerplate that should be preserved by minifiers in the output bundle.