set5v0.972.ic507 (Katana Set5 v0.972, crc32 1a2f2a91, sha1 08df891f) entered MAME's dcdev set in 0.260. It comes from the archive.org item MAME_0.278_ROMs_non-merged_2025, whose dcdev.zip is the TorrentZip of the 0.260+ recipe. It becomes the primary dcdev.zip, and the five-member pre-0.260 set is kept as a variant.
Demul's dc set (11 rows of demul.exe's table) is built with build_torrentzip from members checked against the table's crc32 and sha1, in bios/Other/demul/. Only Demul reads dc.zip, so only its manifest entries move.
Demul 0.7 reads 44 NAOMI BIOS rows from naomi.zip, the HOTD2, F355 and Airline Pilots BIOS among them. No copy held them all. The set is built with build_torrentzip from members already in the collection, each checked against the crc32 and sha1 of demul.exe's table, and kept in bios/Other/demul/. Batocera, KNULLI and RetroBat place it at bios/naomi.zip, the file MAME cores there also open, so it carries the nine MAME members the Demul table does not list.
The resolver left another emulator's own copy out of the member and superset ranking, so Flycast and the MAME cores keep the copies they were served.
Abdessamad Derraz