1  –  topic

    Specifies the topic about which you are requesting information.
    If you specify an incomplete topic name, CDO displays information
    on all topics starting with that string. If you specify wildcard
    characters, CDO displays information on all matching strings.

    If you do not specify a topic, CDO displays a list of all
    available topics, followed by a request for a topic.

2  –  subtopic

    Provides more information, such as parameters and qualifiers,
    associated with this command. A subtopic can also be a
    description and examples of a command.