To create a new security rule, navigate to Documents > 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 document.
This setting is useful if you require data to be passed to web pages that your document is linking out to.
You will not need to consider this setting for the vast majority of the documents you create.