Posting style
When a message is replied to in e-mail, Internet forums, or Usenet, the original can often be included, or "quoted", in a variety of different posting styles.
For a long time the traditional style was to post the answer below as much of the quoted original as was necessary to understand the reply (bottom or inline).
In an e-mail reply, it is sometimes appropriate to include a full or partial copy of the original message that is being replied to; due to the asynchronous nature of Internet communication, people often engage in many conversations at the same time, and email responses may be received long after the original message was sent.
For these reasons, the original poster may not be aware of what message a post is intended to be a response to, and providing context is helpful.
Many email reading programs (mail user agents) encourage this behaviour by automatically including a copy of the original message in the reply editing window.
The convention of quoting was common in Usenet newsgroups by 1990, and is supported by many popular email interfaces, either by default or as a user-settable option.
Doing otherwise may confuse the reader and also e-mail interfaces that choose the text color according to the number of leading markers.
[2] Sometimes an indicator of deleted text is given, usually in the form of a square bracketed tag as: "[snipped]", "[trimmed]", or simply "[...]".
Also, when replying to a customer or supplier, it may be advisable to quote the original message in its entirety, in case the other party somehow failed to keep a copy of it.
Interleaving was the predominant reply style in the Usenet discussion lists, years before the existence of the WWW and the spread of e-mail and the Internet outside the academic community.
[citation needed] The style became less common for email after the opening of the internet to commercial and non-academic personal use.
[citation needed] One possible reason is the large number of casual e-mail users that entered the scene at that time.
[citation needed] Finally, most forums, wiki discussion pages, and blogs (such as Slashdot) essentially impose the bottom-post format, by displaying all recent messages in chronological order.
This appears to be advantageous for business correspondence, where an e-mail thread can dupe others into believing it is an "official" record.
[citation needed] By contrast, excessive indentation of interleaved and bottom posting may turn difficult to interpret.
[citation needed] In the earlier days of Usenet informal discussions where everyone was an equal encouraged bottom-posting.
Newer online participants, especially those with limited experience of Usenet, tend to be less sensitive to arguments about posting style.
[4][5][6] Top-posting is a natural consequence of the behavior of the "reply" function in many current e-mail readers, such as Microsoft Outlook, Gmail, and others.
[dubious – discuss] Moreover, a bug present on most flavours of Microsoft Outlook caused the quotation markers to be lost when replying in plain text to a message that was originally sent in HTML/RTF.
[7][8][9][10] Top-posting has always been the standard format for forwarding a message to a third party, in which case the comments at the top (if any) are a "cover note" for the recipient.
It also gives the sender freedom to arrange the quoted parts in any order, and to provide a single comment to quotations from two or more separate messages, even if these did not include each other.
Top- and bottom-posting are sometimes compared to traditional written correspondence in that the response is a single continuous text, and the whole original is appended only to clarify which letter is being replied to.
[11][12] Especially in business correspondence, an entire message thread may need to be forwarded to a third party for handling or discussion.
On the other hand, in environments where the entire discussion is accessible to new readers (such as newsgroups or online forums), full inclusion of previous messages is inappropriate; if quoting is necessary, the interleaved style is probably best.
If the original message is to be quoted in full, for any reason, bottom-posting is usually the most appropriate format—because it preserves the logical order of the replies and is consistent with the Western reading direction from top to bottom.
However this also results in some portions of the original message being quoted twice, which takes up extra space and may confuse the reader.
An untrimmed quoted message is a weaker form of transcript, as key pieces of meta information are destroyed.
This example is occasionally used in mailing lists to mock and discourage top-posting:[13][14][15] Bottom-posting preserves the logical order of the replies and is consistent with the Western reading direction from top to bottom.
