http://netbsd.i2p/docs/guide/en/chap-inetd.html
This file
basically contains information mapping a service name to a port
number. The format of the /etc/services file is: service-name port-number/protocol-name [aliases] "service-name" is the name of the service, "port-number" is the
port number assigned to the service, "protocol-name" is either
"tcp" or "udp", and if alias names for a port are needed, they
can be added as "aliases",...