Anonymous posting: if you leave the "Name" blank, your default name will be "Anonymous."
At the top of each post is "ID:" followed by eight random letters, numerals, or symbols. This is to identify the person posting, in case people post under the same name. It is based on IP addresses, so posting under different IP addresses will result in different IDs. However, please note that your "ID:" is the same only if you post in the same thread, and will appear differently when you post in different threads.
If, for any reason, you think that it is important to distinguish your identity, you can use a tripcode by typing a number sign (#) after your name, followed by a secret string. This "secret string" should be only eight characters long, since any characters after the eighth is ignored, and it is advisable that your tripcode be a bunch of random numbers and letters. Here is an example of what you type into the "Name:" box in order to use a tripcode:
Name#b8f9sj3i
The result will be "Name◆xTSWgtBmh2" as your name. Please note that whereas the name is bolded, the tripcode is not bolded.
To scroll up and down, one can obviously use the scroll bar on the side, or one can press the up and down arrows once one has clicked once on the web page. However, there are four other buttons on the keyboard that maybe be quite useful.
If there was a thread that you have seen before, and would like to see it again, but have difficulty finding it in the list, you can press Ctrl + F (or command + F for Mac users), and then type in the thread title to find it.