Two problems:
There's a category of the listing "Series" which essentially means "System", i.e. "RMFRP", "HARP", "D20"
That could be resolved by putting it in multiple times. . .i.e. the "EoH (RMFRP)" or "EoH (d20)" etc.
The other field is "Publisher" which is not ICE, but I didn't know what to put in. Hence, my post.