IMLock - Whitelisting
Whitelisting is setting the program to *not* block certain sites.
Whitelisting is useful for things like your company site, or another site you may use all of the time, and never want blocked.
In some cases, you may want to block all sites *except* a whitelisted site.
If a site is set to be blocked, but is also Whitelisted, the
site will not get blocked, because whitelist is the priority.
You should whitelist sites that you never want blocked.
You should whitelist your own domains.
With IMLock, you can whitelist sites, and set a checkbox to
block all sites except those whitelisted. That way your users will only
be able to access sites you choose.