To create a new security rule, navigate to Publications > Settings > Security Rules and select Add.
This article will cover the security rule Params:
Params are small pieces of information that are appended to a URL. Ticking this option will allow any incoming parameters to be appended to any outgoing links within your publication.
This setting is useful if you require data to be passed to web pages that your publication is linking out to.
You will not need to consider this setting for the vast majority of the publications you create.