In all recent netscape packages, "movemail", "movemail-src" and "spell" are packaged in netscape-common. Yet they are of absolutely no use to netscape-navigator users, only to netscape-communicator users. (Indeed, in Netscape's sources, these aren't packaged with "navigator-v472-export.x86-unknown-linux2.2.tar.gz", only with "communicator-v472-export.x86-unknown-linux2.2.tar.gz".) Unless there is a higher philosophy of only having the differing binary (and two links) in the navigator/communicator packages, the above mentioned stuff belongs in "netscape-communicator" and not "netscape-common".
Fixed in the -6 build.