[Koha] OPAC "lists"

Our OPAC has a limit of 10 public lists. We would like to add a few more but cannot seem to access the area where we would make this change. We noted that other KOHA libraries have many lists. Can someone help? Thanks! Barbara L. Keef Reference & Technology Librarian Windham Public Library 217 Windham Center Rd. Windham, Maine 04062 207-892-1908