Netiquette

Netiquette is the etiquette of using the web. Similar to etiquette in the real world, netiquette governs how one should behave. Some forms of netiquette include:

1. Being oneself on the Internet. Behind a computer screen, it becomes easy to one to say things they wouldn't say in real life. One should make sure what they say on the Internet is consistent with what  they would say in the real world.  
2. Being clear on intent. Sarcasm should be used sparingly, if at all, because reading text on the web could be misinterpreted, since there's no body language to back up the intent of what one's saying. 
3. Not using all-caps when sending an online message. Proper punctuation and spelling should be used at all times.

One would use netiquette when engaging in an e-mail for professional purposes, such as listing a complaint to  customer service. My own netiquette is fairly good, but could use some improvement. I make sure to use proper punctuation and capitals where necessary, even outside of professional purposes. This has the side effect of me sounding too formal when sending text messages to friends.