## Chapter 16. Out-of-band server data

KildClient support some protocols that allow the server to send data to the client in a way that can be easily parsed (unlike prompts, for example) and that is not directly visible to the user. We call this out-of-band data. For example, the server could send your character stats (hp, mana, etc), so that a plugin can display this data in a more convenient form.

Currently, two such protocols are supported: MSDP and GMCP (sometimes called ATCP2).

By default, nothing is done with the data that is received. A hook must be bound to the `OnServerData` event to handle the data that is received. Even so, KildClient does nothing with the data (other than to parse it in a form that's easy to be used in Perl scripts and protocol-independent): it's up to your code to do anything with it. For example, KildClient does not store any previous values of any variable, it is up to you to store what you want.