Double blank (from entries created  before 1.7f) is internally translated
to // which means "all topics" (nothing  to do with JCL, this is just the
last character in the MIME base64  table). When 1.7f creates an entry, it
always  supplies  something   in  that  field  based  on   the  value  of
"Default-Topics=" or the  topics selected by the  user. Unfortunately, as
you pointed out the default for that keyword is NONE (coded as AA) rather
than ALL and this is not what the list owner expects. I will fix this for
the next release.
 
  Eric