648eb34d____Setting_Prelude_preferences__Option
[Description] The ID number is a unique value associated with an asset. It enables the application to recognize a file even if the filename has changed. Each application can use this information to manage cached previews and conformed audio files, preventing additional rendering and conforming. When this option is selected, XMP ID values are written to source files when they are imported into Prelude. If a file already has an XMP ID, then Prelude doesn’t write a new one, and no change is made. Files from recent versions of Adobe applications will, in general, already have an XMP ID. Important: The Write XMP IDs To Files On Import preference only controls whether unique ID values are automatically written to files during import. This preference does not control whether XMP metadata is written to a file under other circumstances, such as when you edit metadata in the Metadata panel. [Option] 
Write XMP ID To Files On Import
Prelude Help | Setting Prelude preferences