> to prevent access from other packages

Doesn't work that way – there's already the default visibility for that. AFAIK it works like this: `@Restricted(NoExternalUse.class)` prevents use by e.g. plugins (that need to consider this annotation by using the access modifier checker that is part of the same component), even if they have classes in the same package. Nobody would really care about its visibility, as it can always be changed, including code that uses it – except, due to plugins, once it's accessible and released, someone might use it and removal will break that plugin. [See Javadoc here](https://github.com/kohsuke/access-modifier/blob/master/access-modifier-annotation/src/main/java/org/kohsuke/accmod/restrictions/NoExternalUse.java), and the [general documentation for this](http://kohsuke.org/access-modifier/).