This is simply the way the program LISTSERV uses for UUENCODE works (it has its own reasons which were explained to me once and which I promptly forgot - it was designed for PC software). UUENCODE is not a file transfer format like Netdata, it is a way of translating a stream of binary bytes into a stream of non-binary bytes that mailers will usually leave alone. In the particular case of transient MODULEs, there is a rather legitimate case for wanting to use UUENCODE to retrieve the file, but what about regular MODULE's? Eric