AT Internet natively distinguishes natural sources (direct access, referrer site, webmail, etc.) and marketing sources that correspond to the traffic generated by campaigns (emailing, advertising, etc.)
On top of the default natural sources, you can create your own custom organic sources (up to 5 different sources). These custom sources are composed of families, themselves composed of rules defined on the basis of the characters composing the referrer domain.
A frequent use-case of this feature is to create a custom source to sort all traffic coming from organic social media. You could declare a family for each social network you want to include in this source.
Custom Organic Sources can be configured from the Settings menu, providing that your account has the right level of access.