Defines which is the "scope" of this Backlog:
global
means that it will include all tickets in the DB
milestone
means it will include only the tickets assigned to a certain milestone,
sprint
means it will include only the tickets planned for a specific sprint.
By default, global backlogs will not show any planned tickets. A ticket is planned if it's
milestone and/or sprint field has been set to a specific milestone/sprint. The setting to
include planned tickets is only meaningful for global backlogs.
All the linked tickets will be included as well, according to the defined hierarchy.