This article is from the Digital Broadcast Satellites FAQ, by Brian Trosko email@example.com with numerous contributions by others.
Few things are as annoying as paging through 100 lines of quoted text, only
to fine "Me, too!" at the end. When posting a follow-up (reply) to a message,
delete all but the specific parts you are replying to. In most cases,
you can trim to a sentence or two. Trimming the quoted material also
makes it easier for readers to see which points you are responding to. If
you are not replying to a specific part of the article, but have points
based on the previous article, you might wish to delete the entire article
and just post a brief summary, i.e. [Snip long DSS vs. BUD post].
Quoting someone else's .signature file is generally considered to be obnoxious.