Internet obscuridae for today. These sites were the first few members of one particular “system” that was very popular among websites of years ago. What system?

1. bendall.de
2. crypt.eldritchs.com
3. www.qrq.de
4. kloth.net
5. qsl.net
6. …

Hint:

• FOLDOC
• 

Q will be up for 12 hrs longer.

Cracked by Logik, Raghuvansh, Rogi, udupendra, varuns88, byslexia, BASAB, madhur, Dibyo, Ps, sidsen and Chinmaya U.Holla