<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.
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Nearby terms: topic drift « topic group « topic map « topic thread » top-level domain » topology » TOPS-10