Tabs, which represent Documents within a TabbedView, can be pinned at runtime. Pinned tabs are placed before unpinned ones. A pin-able tab displays the Pin Button next to its Close Button (see the figure below).
The IDocumentDefaultProperties.AllowPin property, accessible via the Document.Properties object, specifies whether the current Document can be pinned. To enable or disable this feature for all Documents within a Tabbed View, use the IDocumentProperties.AllowPin property instead, which has a lower priority than the IDocumentDefaultProperties.AllowPin property.
You can show or hide Pin Buttons via the ShowPinButton property. This property is also overridden for individual Documents via the IDocumentDefaultProperties.ShowPinButton property.
Moreover, you can set whether Pin Buttons are displayed in active, active and focused or all tab headers via the IDocumentGroupProperties.PinPageButtonShowMode property.
Use the Document.Pinned property in code to pin/unpin individual tabs.