topic thread

from The Free On-line Dictionary of Computing (8 July 2008)

topic thread

   <messaging> (From {Usenet}, {GEnie}, {CompuServe}) A more or
   less continuous chain of postings on a single subject, sent to
   a {forum} such as a {Usenet} newsgroup.  To "follow a thread"
   is to read a series of postings sharing a common subject.

   On Usenet these are connected by "Reference" headers.  The
   better {newsreaders} can present news in thread order
   automatically.

   (2008-02-06)