This option is a Yes/No (or Boolean) value and functions the same way as the Flag as Privileged check box. Use this flag as a temporary marker for items you wish to review at a later time (or print, annotate, etc.). This option has no real coding meaning, but is just an additional means of marking an item for quick retrieval.
When this flag is checked, you may run a Coding Search for Item is flagged to generate a list of all the flagged items.