Guidelines

1. Avoid "flames". Flames are real wars usually burst in consequence of a misunderstood. In fact misunderstanding is extremely easy on the net, because you can't see your interlocutor. For this reason someone invented 'smiles'. So beware of sarcasm. I think you should think two times before reacting to a presumed affront. Smiles are very helpful here, because they 'show' your real mood. For example, if you are joking, you could use a smile like this: ':-)))'. If you are discussing with several people (for example you are inside of a newsgroup) absolutely avoid flames. If you can't avoid that, use private email messages. If you must absolutely to polemize, use the 'FLAME ON' and 'FLAME OFF' flags. For example:
   FLAME ON:
   Notice that I want to polemize here, and I know these words are useless. This type of argument is not worth the bandwidth it takes to send it, I know.
   FLAME OFF
   If you notice a flame, I suggest you something: just don't reply. I think this is the best way to extinguish flames.
2. Avoid "spamming". If you are sending the same message to several sites you are performing a spamming action. Think of users that open their mailbox and have to download huge quantities of unsolicited messages. They *pay* for using the net, not for unsolicited messages.
3. Avoid huge messages. For example a little message with a huge signature. Or messages containing huge attachments such as pictures, postscript documents and so on. A signature no longer than 4 lines is an accepted practice. For the same reason, avoid excessive "quoting". When you 'reply' to a message, the whole message is 'quoted' by your email client. In other words the recipient will receive both its 'quoted' message and your answer. You can't quote the whole message just to answer: 'Yes, I agree'. You have to cut and paste messages in order to point put the object of your answer. Insert something like 'snip...' to point out that you have done a cut. So: do not quote the whole message. Remember that many people pay for connectivity by the minute, and the longer your message is, the more they pay. Sometimes I see email with a whole HTML page pasted at their inside. Usually 'veterans' aren't really kind with sender of these messages.
4. Don't write whole phrases using only capital letters. When you use upper case letters, the recipient of your message will understand THAT YOU ARE SHOUTING! So, when you want to point out some words, use asterisks for *pointing out* your words. You can also use underscore symbols so: now I'm _pointing out my words_.
5. Pay attention to the subject. When you send an email or you post a message to a newsgroups, pay attention to the subject. It should be clear. Avoid subjects like this: 'Help'. Suppose you have problems with a server. You could write: 'Server problems' into the subject field instead of: 'Doesn't works'. For the same reason, pay attention to the 'Re:' header. It is helpful for the first reply (it shows the subject of the previous message to which you are replying), but the same 'Re:' is quite useless for the *ninetieth* reply. In addition, avoid 'Off-topic' subjects. An off-topic message is a message that has nothing to do with the "thread". A thread is a discussion about a particular subject.
6. Avoid chain letters. Chain letters are forbidden on the net. They are an useless waste of bandwidth.
7. Avoid "cross-postings". When you post the same message to several different newsgroups you are performing a cross-posting action.
8. Read the appropriate FAQs before asking. Don't be surprised to receive a 'RTFM' (Read The F
   ing Manual) message when you are asking 'the same old question'. There are several questions going around the net that are always the same. For this reason people write FAQs. FAQs (Frequently Asked Questions) are documents where you can find those questions and the corresponding answers. So read the appropriate FAQ before asking.
9. Don't be intolerant with newbies. When you notice grammatical errors or mistakes, don't point out them uninterruptedly. In addition you should be kind with newbies (don't forget when you WERE a newbie yourself) and their questions. Even if you are in the net since a lot of time, I think you are a newbie yourself when you are intolerant with real newbies, because you don't know the netiquette.
10. Pay attention at cc's when replying. Don't continue to include people if the messages have become a 2-way conversation.
11. Avoid particular characters. Do not include control characters or non-ASCII attachments or particular font or accents. Use quotes instead of accents. If you are using the Italian language you have a problem unknown to the English language: accents. The net was developed thinking about the English language, so you can use only a restrict set of ASCII characters (where there aren't letters like these: à, è, é, ì, ò and ù). Although there aren't problems with the MIME protocol, when the sender or the recipient of an email don't uses it, the result could be unreadable. So use quotes, in this way: a', e', i', o', and u'. Limit line length to less than 65 characters and end a line with a carriage return.
12. Read both mailing lists and newsgroups for one to two weeks before you post anything. This helps you to get an understanding of the culture of the group. For example, advertising is welcomed on some lists and Newsgroups, and abhorred on others. So you should know your audience before you post. Unsolicited advertising which is completely off-topic will most certainly guarantee that you get a lot of hate mail. Besides almost all newsgroups should have their charter/guidelines posted regularly.
13. Be aware of time zones. When you are transferring big files via FTP, you should pay attention at time zones. In fact you should transfer those files when the interested FTP server is not too much busy (by night for example).

To know more

• Netiquette, by Virginia Shea, Table of Contents and Welcome Page
• The Net: User Guidelines and Netiquette Translations
• Arlene H.Rinaldi Netiquette Guide
• Communicating on the Internet