This means you can have the Flash player installed on your Mac, but blocked for your wider web experience, while still being allowed on a few select sites that you trust the plugin to run on. This serves as a perfectly reasonable alternative to uninstalling the plugin in it's entirety, and it's easy to configure for all websites and selective websites in Safari for OS X.

• Open Safari and then go to "Preferences", accessible from the Safari menu.
• Choose the "Security" tab and look for "Internet plug-ins", then click the "Manage Website Settings…" button.
• Select "Adobe Flash Player" from the left side to gather a list of websites that have used or attempted to use the Flash plug-in.
• Pull down the menu alongside each URL to fine-tune Flash for that website, choosing one of five options:

Ask – Safari will ask permission to run Flash if it is encountered.

Block – blocks all Flash for the website from automatically loading, this is essentially like Click-To-Play and can be overruled by selecting a Flash object and choosing to run.

Allow – Flash will always run when encountered for that specific website.

Allow Always – Flash will always run when encountered for specific websites, even if the Flash plugin has been disabled due to being outdated or insecure.

Run in Unsafe Mode – not recommended, overrides any security preferences within Safari to give Flash free reign to run.