A whitelist or blacklist group is a collection of whitelist tags or blacklist tags that can be assigned to as many sources as you like. Rather than creating tags source by source, this gives you the ability to create groups of tags that can be toggled on and off. For example, if rasa.io only wanted articles regarding artificial intelligence from Stanford Social Innovation, then we could create a whitelist group called 'AI tags' that would have multiple tags pertaining to artificial intelligence. Or for example, if rasa.io did not want any articles coming in from Science Daily regarding political topics then we could create a blacklist group called 'political tags' that would have multiple tags pertaining to politics. When you are editing a particular source and you create a tag group while editing that source, that group of tags can then be added to subsequent sources.