I’m trying to deal with a release by Michael W. Smith. One of my Christmas releases is a cardboard box with its own barcode (8713542007919) titled ‘The Christmas Collection’. Inside the box are two regular jewel-cases of the existing releases ‘Christmas’ and ‘Christmastime’.
How do I handle this ‘box-combo’ without duplicating data in the database.
You will have to repeat some data. What you hold is an “Album,Compilation” of two releases.
Add a new Release, in a new Release Group. Enter the box barcode into the barcode field. If you want to take note of the other two barcodes, then put those details into the annotation. It is only the external barcode that is technically relevant for the “Release”.
When adding the track, on the Tracklist page you can use Add Medium button and then Existing Medium
This way you can quickly add the tracklists of both CDs, and link to the Recordings that are already in the database.
Once your Release is added a nice touch is to go to the Release Group and then use the “Includes/Included In” Release Group relationship to point to the two Release Groups of “Christmas” and “Christmastime” to link it all together.
Not sure if it would be of any assistance, but 2009, after the release of his 3rd Christmas album, Smitty released a 3 disc compilation: https://musicbrainz.org/release/112d4230-66d4-415e-8c05-e2a58ff9ac0e.
I’m aware of that release, but that’s not the one I have in my CD-rack 
