Namespaces are attributes of packages used to better organize them. A namespace can be created by a user and packages can be subsequently published under it. A namespace is owned by a single user that can publish under it. A namespace can be shared with other users to grant them publishing rights.
ztc namespace create name
will create the namespace
name and associate it with the user.
There is a limit on the number of namespaces a user can own and the command fails if the limit is reached.
ztc namespace list
retrieves the list of the user namespaces.