Why do I need a dumpuser account?

[mindfuq]

I started reading the "Setup the Backup Client Hosts" section of the
Amanda docs, which immediately assumes that I have a folder
"~dumpuser/".  It's telling me to create an ".amandahosts" file within
that directory.  Portage did not create any such user.  Is this a user
that I need in addition to the "amanda" user?  The client and server
are the same machine in my case (for now).