DEPRECATED: Child list topics
A functional topic that maintains a list of child topics and notifies subscribed clients when a child topic is added or removed directly.
A child topic is a topic that is directly beneath the child list topic in the topic tree. For example, if the child list topic is at the path foo, the topics foo/bar and foo/fred are its child topics. However, the topic foo/bar/baz is not a child topic of foo.
Why use a child list topic?
You can use child list topics to group sets of related data items. Each data item is a child topic beneath the child list topic. A client can subscribe to the child list topic and receive a notification when data item is added to a set (that is, when a child topic is added or removed).
Considerations when using a child list topic
Child list topics are supported only by the Classic API.