Many of this label's releases have individual disc cat#s and, more importantly, barcodes. These should not be treated as individual releases, even if they're being re-sold in all shapes and forms all across the web. Note down the disc barcodes in the release annotation. Disc cat#s often come in the form 54321/#; note this down as 54321 for the release, and, as a second cat#, 54321/1-23 for the discs, if that release is a 23-disc release.
On releases imported to the US, one can find a sticker with a barcode that starts with (0)84 (→ Example). Do not add an extra release for this, but note it down in the annotation as being the US import barcode. For the barcode field, use whatever's under that sticker. If there's nothing, check the "This release has no barcode" box.
The usual barcode starts with 50284 (in the case of 5-digit cat#s), or 50293 (in the case of 4-digit cat#s).
5-digit cat#s usually denote an XE release (mostly with STEMRA rights society logo).
4-digit cat#s usually denote ... I don't know what (mostly with MCPS rights society logo).