That's referring to having multiple mailing lists linked together
     for
     the cypherpunks list. Basically, you would mail one address and it
     would
     mail the other mailing lists, sort of like an old school FidoNet
     echomail board if you remember that.

   I probably used fidonet and didn't realise what it was.  I was pretty
   young when I dialed in to bbs's.
   Regarding CDR, I found [1]https://web.jfet.org/cpunk/howto.html .  It
   vaguely sounds to me like a CDR system could be revived by adding
   X-Loop header support to mailman.  Not sure.

References

   1. https://web.jfet.org/cpunk/howto.html