It's a good idea to make these suggestions part of your normal news posting habits, because people with bad netiquette often get abused or flamed on groups which are less friendly than Callahan's. When you follow-up to an article, please edit out everything from the quoted article except the specific points to which you are replying. It's nice to see a little of a previous article for a reminder, but most patrons will already have read the whole thing before, and won't need to read it all over again. It can be extremely annoying to see a page or more of quoted text, and then only two original lines at the end of the article. It is almost always possible to get away with quoting much, much less than that.
Many people read news via modem lines, or by downloading the articles in bulk.
Excessive quoting costs all of these people both time and money. Please be considerate. If you do quote someone, please include a blank line between the end of the quoted material and your reply. Although it looks like a blank line on a screen, that extra carriage return is only one character - so it makes almost no difference to the true length of your message, and it makes it so much easier for readers to see where you have started talking. Before you reply to a post, ask yourself whether replying by e-mail will be okay.