Aren't they just the manufacturer? Generally we don't put them in the entries, otherwise we'll have to update almost every sony album in the db, as well as others (Starchild comes to mind). Recently Lantis was removed from Mellowhead entries for example, which is kinda the same thing as this.
I haven't checked any recent ones but for example in this one (last year) I would just use ariola (only their logo on obi and disc)
http://vgmdb.net/album/53608
Not sure what the original intention of omitting manufacturers was, maybe because every release of a label is manufactured by their parent company so it's not worth mentioning?