那位老大能不能具体解释proftpd.conf各项意义

Question

具体内容如下
# This is a basic ProFTPD configuration file (rename it to
# 'proftpd.conf' for actual use.  It establishes a single server
# and a single anonymous login.  It assumes that you have a user/group
# "nobody" and "ftp" for normal operation and anon.

ServerName                      "ftp.sail.coma"
ServerType                      standalone
DefaultServer                   on

# Port 21 is the standard FTP port.
Port                            21
# Umask 022 is a good standard umask to prevent new dirs and files
# from being group and world writable.
Umask                           022

# To prevent DoS attacks, set the maximum number of child processes
# to 30.  If you need to allow more than 30 concurrent connections
# at once, simply increase this value.  Note that this ONLY works
# in standalone mode, in inetd mode you should use an inetd server
# that allows you to limit maximum number of processes per service
# (such as xinetd)
MaxInstances                    30

# Set the user and group that the server normally runs at.
User                            nobody
Group                           nobody

# Normally, we want files to be overwriteable.
<Directory /*>;
  AllowOverwrite                on
</Directory>;

# A basic anonymous configuration, no upload directories.
<Anonymous ~ftp>;
  User                          ftp
  Group                         ftp
  RequireValidShell off
# We want clients to be able to login with "anonymous" as well as "ftp"
  UserAlias                     anonymous ftp

  # Limit the maximum number of anonymous logins
  MaxClients                    10
# We want 'welcome.msg' displayed at login, and '.message' displayed
  # in each newly chdired directory.
  DisplayLogin                  welcome.msg
  DisplayFirstChdir             .message

  # Limit WRITE everywhere in the anonymous chroot
  <Limit WRITE>;
    DenyAll
  </Limit>;

小弟在此谢谢!