Adding a column in the sprint backlog is simply a matter of adding a definition for it under the Columns section of the configuration mapping file. The Column block has the following structure:
<Column ColumnType="column_name" AssigneeRestriction="[Assigned|Unassigned|All]" AutoAssign="[true|false]">
The AssigneeRestriction attribute allows to configure columns to only hold work items that are either unassigned or that have been assigned to somebody. If a work item is moved from a column that only holds unassigned items to a column that only holds assigned ones, the user selected in the drop list in the toolbar will automatically be assigned to the work item if AutoAssign is set to true. Conversely, if an assigned work item is moved from a "assigned-only" column back to a "unassigned-only" column, the work item is automatically de-assigned. If the AutoAssign attribute is set to false, it will not be possible to move an unassigned work item into a "assigned-only" column and vice versa.
For example, If we want a Task work item with a Ready for Test state to be in a new column called Ready for Test, the following code needs to be added:
<Column ColumnType="Ready for Test" AssigneeRestriction="Assigned" AutoAssign="true">
<State>Ready for Test</State>