Picard can use a different MB server for fetching data, but by default still uses the main MB server for data submission (unless disabled by user option). This is because mirrors do usually not allow submitting data and data should be entered into the main database.

The get_submission_server utility method is used to get the proper URL. However, this is currently only used for opening the URLs for attaching CD TOCs and the addrelease browser integration.

The submission server should also be used for ISRC and rating submissions.