There are limits to the amount of information we can fit into our Character's prompt. However, there may be some information that you want the AI to understand outside of this permanent context.
This is where a Lorebook comes into play. Each item in the Lorebook is a keyword with an associated value. When this keyword is used in your chat, the entry is added dynamically to the chat context so that the model understands what you are referring to.
Lorebooks can be especially helpful for Characters adapted from a fictional world. You can easily define a vast amount of important information about the world without overloading your Character's prompt.
home
A two story house on a cul-de-sac in a middle class neighborhood. {user}'s bedroom is on the top floor. The house is cozy.
In this example, whenever you or your Character mentions "home", the associated keyword and value are added to the context. This data is injected immediately before the last two chat messages. If the Character is supposed to be your longtime friend, this is something they should know, but it's not necessarily something that belongs in the Character's prompt.
Scroll down within Character settings to Lorebooks. Click New Item which will bring up a Keyword / Value pair. Enter as many associated keywords as you like (eg. home, house, pad) and then the associated entry. Then, save your changes and you are ready.
Note that the number of tokens allowed to be used by Lorebooks is limited to 384 tokens, so as not to prevent your chat history from being completely removed. As such, it is recommended to write concise entries for each keyword. Remember that you may have more than one Lore Item triggered at one time, so they can add up quickly.