I keep seeeing messages that blast people for doing it, but I don't know what it means. By virtue of that, I very well may have done it at some point (for which I retroactively apologize). I looked in the FAQ, but it didn't say anything about it.
It's like this...I've posted my reply over your original message, which the self-proclaimed net-cops will flame you for. A lot of people get their panties in a bunch over it, but unless you're posting a long reply, I don't see what the big deal is.
Top posting is when a reply is posted above the message that is being replied to. It's becoming a convention in e-mail where it makes no big difference since e-mail involves usually only a couple of people and limited replies.
On usenet it's common for there to be multiple replies from multiple posters. Threads develop and top posting messes up the continuity of threads. It's easier to be able to follow a thread sequentially by reading the chain of replies from top to bottom, so that if one wants to make reference to a prior message one need only scroll up. That loss of continuity is what annoys many usenent users and causes them to flame top posters.
It's a method of screwing up the English language so that all new replies appear ABOVE the original text, instead of below it as with any normal method of English (or most other languages) writing.
It's a bit like writing a book by starting near the end, writing a few paragraphs, then moving back up the page a bit, writing a few more BEFORE the first bit, then again and again. It might make sense for a single short reply, but as soon as there's a third entry in the reply thread it's just a bloody awful mess.
If you think of the history of reading, it's been that for a long time and seems to work well, Usenet posting and emails being an extension of that. Try telling a joke but giving the punchline first to see if it works with your mates! :-)
I prefer top posting. I like to see what the new poster has to say right off the bat. I don't need to scroll down through previous post that I probably have already read to try to fine the new material. If the previous posts have been properly trimmed, to remove the non-pertinent material, top or bottom posts should both be easily accessible.
My two cents. I belong to one mailing list that requires top posting. There are fans of each. I think it depends on the length of the message being replied to. A short one such as this is fine either way.
If you are replying to a VERY long message, more than a screenful, and you do not edit down the message, then top posting becomes more readable.
Actually, the best bet is to edit the message down to a specific sentence or two that you are specifically replying to.
Also, in a thread with many previous replies, consider editing out only the last reply, the one you are replying to. No need to enclose all twenty previous comments.
Top-posting is the usenet equivalent of belching in public or chewing with your mouth open. It doesn't really hurt anyone, but it shows a certain character (or lack thereof.) To define, it's the act of posting your comments above the previous comments, in reverse sequential order. Most netiquette guides recommend against it, or don't mention it.
Really, the lack of consideration isn't from top-posting itself, but the lazy lack of trimming that most top-posters engage in. You can get thousands of lines of reverse-sequential material for a one-liner or a "LOL" post. That almost never happens with proper-posters. Full-quoting is definitely poor netiquette.
Here's a nice summary with embedded links:
Here's some addtional stuff:
Most of the objection to this "rule" of netiquette comes from lazy top-posters, who will defend their "right" to belch in public, chew with their mouth open, or whatever other behavior they do, and if you don't like it, you can "get over it." After all, since it makes the most sense *to them*, to hell with anyone else, right? *burp* ;)
... and it is perfectly OK to the greedy thoughtless lazy bastards who took it (lunch money) from them. It's used in business because it's the way most message programs place your cursor and most 'business' people are too stupid to figure out how to change that.
On the other hand, anyone with half a brain interleaves a reply to the portions of the message that are relevant. In this way, it makes more sense to the reader. Never apologize for being sensitive or for asking reasonable questions.
That's because there is no FAQ. This is Usenet ...