To post a
followup in a
newsgroup where the
reply is situated above the
quoted text. It's generally agreed that the reply should go below a suitably
trimmed quote of the parent message. Top posting will usually result in a deluge of
flames,
plonks, and pointers to "
HOWTO: Post on Usenet" documents.
One of the many things that people get all pedantic about on USENET.