The Solomon Kane: The Original Marvel Years Omnibus, like many of Marvel's omnibus books, has a regular edition and a direct market variant. The database lists these as Book #1 and Book #1/HC, respectively. To be consistent with other Marvel hardcovers that have regular and DM variants, these should really be listed as Book #1/HC and Book #1/A, respectively.
This would require changing the existing Book #1 to Book #1/HC and changing the existing Book #1/HC to Book #1/A.
Thanks!