One of the many new features in LabVIEW 2013 is the ability to bookmark tasks, or to-do items, using hashtags (#) in labels and block diagram comments. These bookmarks are managed with the LabVIEW Bookmark Manager, available from View > Bookmark Manager. The Bookmark Manager API is open and extremely customizable.

The Bookmark Manager with Block Diagram Preview is an example of how to customize the bookmark manager. This manager is a modification of the built-in manager. It includes a picture control on the right side of the dialog that shows a preview image of the bookmark on the block diagram.

More details on Bookmarks in LabVIEW 2013 and the LabVIEW 2013 Bookmark Manager can be found at the following resources:

http://zone.ni.com/reference/en-XX/help/371361K-01/lvupgrade/labview_features/#Block_Diagram_Enhancements
http://zone.ni.com/reference/en-XX/help/371361K-01/lvdialog/bkmk_manager_moreinfo/
http://zone.ni.com/reference/en-XX/help/371361K-01/lvhowto/creating_bookmark_manager/