Check this box if you want to completely reset the directive to 'none' without inheriting any
values from other directives.
Otherwise, if a fetch directive is unspecified, the web browser will check certain other directives for the effective value.
For example, if script-src-elem is unspecified, the browser will use script-src instead.
If that is also unspecified, the browser will use default-src instead.
Jenkins's internal model of Content Security Policy implements similar behavior, in that specifically allowing a
scheme, domain or other value for a directive will apply in addition to what would be the fallback value.
For example, Jenkins by default defines script-src but not script-src-elem.
If an administrator specifies a value to be added to script-src-elem, Jenkins will apply that
in addition to the value for script-src.
Checking this box disables this behavior.