Sheila King just posted an excellent list of references and summary about quoting of text in email messages (when you respond to a posting or email using a "reply" command and include some text from the original message):
Here are several references which explain why the inline quoting is preferable. It really boils down to actual discussions taking place, in which many people may be participating. Without properly nesting the quoted material, it can be extremely difficult for someone reading the post later to figure out the attributions and their source.
- A description of the traditionally accepted quoting style in newsgroup postings.
- Mailing and Posting Etiquette section entitled Post In-line for Context.
- Netiquette and practical hints with examples.
- The advantages of Usenet's quoting conventions.
- Bottom vs. top posting and quotation style on Usenet.
I've been wanting a list of references like this for a while - I just never got around to compiling it. Thanks Sheila :)