Idiomatic way how to "share" artifacts betweens modules beside placing in the "module" root package

[maku]

I am curious what would be an idiomatic way to share artifacts across "module" (package) boundaries (e.g. entity's, DTO's)

The default is that everything that is in the root of a "module" package is available for other modules. However, I would also like to have a reasonable package structure within a module package (e.g. application, domain etc.) .

The question is: how do this "right".

Is it good practice to use @NamedInterface for this? (e.g. place it directly on a class / interface, use package-info.java)

[odrotbohm]

The most idiomatic way would be to establish a core module and declare that as open if need arises to decompose it into sub-packages.