There is no DH under NF code. There are many ways to utilize the DP/Flex option. Both of these links are pretty good explanations of some different scenarios. This is NOT the same as using an EP in USSSA.
http://www.ihsaa.org/dnn/LinkClick.aspx?fileticket=3NOkANiVt5c%3d&tabid=80http://www.fastsports.com/tips/tip25/index.shtmlA couple of easy reminders:
The DP can never be on defense only.
The FLEX can never be on offense only.
The DP and the FLEX can never be on offense at the same time.
The DP and the FLEX CAN play defense at the same time. .