http://www.aikencolon.com/Miller-Fall...

A personal fall arrest fall protection system consists of three devices
anchor point & connector
full body harness
connecting device

The only acceptable type of OSHA fall protection / fall arrest body wear is a full body harness
Full body harnesses should be selected on the type of work, environment, size of the user (height and weight) and applications necessary
Side D rings are meant for positioning only, and are not acceptable as the only means of connection to a connecting device
Front D rings are generally used for retrieval, decent, confined space systems, and positioning. Just like side D rings, a front D ring is not an acceptable means to connect to the connecting device