When creating a group channel, you can additionally specify a custom channel type to subclassify open or group channels. This custom type takes on the form of a
std::wstring, and can be useful in searching or filtering open or group channels.
custom_type properties of a channel object allow you to append information to your channels. While both properties can be used flexibly, common examples for the
custom_type include categorizing channels into School or Work.
custom_type property contains the channel's custom type.