A fan club for One of the greatest bands of all time, AFI. It costs thirty dollars to join, and all who join get a special package and special advantages.
Guy: Dude! I joined the DF!
other guy: Dude! I'm so jealous! That's a hardcoregroup of fans! and you get special stuff!
Guy: Dude! I know!
A hardo is a person who tries extremely hard at everything. Most times a hardo will try very hard at things that do not require excessive effort. For example, sports practices, gym class, etc.
Wow did you see Jack at practice today? What a hardo!