Behavior when displaying content from matched URLs.
'allow': The content url is allowed. 'block': The content url is blocked. 'browser': The content url is blocked and it is opened in the system's default web browser.
Behavior when displaying content from matched URLs.
'allow': The content url is allowed. 'block': The content url is blocked. 'browser': The content url is blocked and it is opened in the system's default web browser.